UNI ED FAKULTNÍ NEMOCNICE BRNO NEUROLOGICKÁ KLINIKA LF MU a FN BRNO BEDSIDE NEUROLOGICAL EXAMINATION: SENSORY SYSTEM, MENINGEAL SYNDROME Eva Vlčková, Department of Neurology, University Hospital Brno MUNI MED SENSORY SYSTEM 2 SENSORY EXAMINATION - evaluation of sensory deficits is MORE DIFFICULT {han evaluation of motor deficits - the subjective nature of the examination; - inconsistency in the patient's responses is common; - the types of sensory abnormalities may differ greatly among patients; - patients may not be aware of any sensory deficit (vibration, proprioception...); - or donl describe the problems using apropriate words (confuse hyperesthesia with weakness, impaired proprioception causing the instability when walkig may describe as „vertigo"...). - still represents INTEGRAL PART OF NEUROLOGICAL EXAMINATION - It's important for localization Of the lesion (together with the presence/absence of motor deficits) - the sensory data are always considered in association with evidence of other neurological dysfunction!!! - If the findings are in correlation with the other parts of neurological examination and are anatomically reasonable and consistent, they are considered as being ^objective BASIC ANATOMY - RECEPTORS - Sensory receptor = the part of sensory system which responds to a stimulus in the internal or external environment of an organism. - specialized for receiving specific kinds of stimuli (mechanical thermal, chemical...). - transduce the sensory signal to an electrical signal in related sensory neuron - CLASSIFICATION BY LOCATION: - Exteroceptors occur at or near the surface of the skin and are sensitive to stimuli occurring outside or on the surface Of the body. These receptors include those for tactile sensations, such as touch, pain, and temperature, as well as those for vision, hearing, smell, and taste. - Interoceptors (visceroceptors) respond to stimuli occurring in the body from visceral organs and blood vessels, = the sensory neurons associated with the autonomic nervous system. - Proprioceptors respond to stimuli occurring in skeletal muscles, tendons, ligaments, and joints. These receptors collect mainly the information concerning body position |\/| U l\l I and movement. MED BASIC ANATOMY - RECEPTORS - CLASSIFICATION BY TYPE OF STIMULUS DETECTED: - Mechanoreceptors respond to physical force such as pressure (touch or blood pressure) and stretch. - Thermoreceptors respond to temperature changes. - Nociceptors respond to a variety of stimuli associated with tissue damage. The brain interprets the signal as the pain. - Photoreceptors respond to light. - Chemoreceptors respond to dissolved chemicals during sensations of taste and smell and to changes in internal body chemistry such as variations of O 2, CO 2, or H + in the blood. MUNI MED SENSORY RECEPTORS (skin, joints, muscles) RECEPTOR TYPE AFFERENT AXON MODALITY Muscle spindles Specialized organ involving intrafusal muscle fibers and the associated nerves Large-diameter myelinated axons Muscle length and contraction Golgi tendon organ Specialized organs in the tendons near joints Large-diameter myelinated axons Joint position and rate of movement Pacinian corpuscle Multilayered capsule around a nerve terminal, producing a rapidly adapting mechanoreceptor Large-diameter myelinated axons Touch and vibration Merkel's disk Slowly adapting mechanoreceptor Myelinated axons Touch Meissner's corpuscle Specialized quickly adapting mechanoreceptor Myelinated axons Touch Krause's end bulbs Specialized terminal axon ending Small myelinated axons Thermal sensation Free nerve ending Branched terminal endings of axons Small myelinated and unmyelinated axons Strong tactile and thermal stimuli, especially painful inputs According to : Misulis KE. CHAPTER 30 - Sensory Abnormalities of the Limbs, Trunk, and Face. In Bradley WG, Daroff RB, Fenichel GM, Jankovic J. Neurology in Clinical Practice, 5th ed. London: Elsevier 2008. UNI ED SENSORY RECEPTORS AND AFFERENTS - —► particular receptor is related to particular nerve fiber type - In general, NOCICEPTIVE afferents are small myelinated and unmyelinated axons. - NON-NOCICEPTIVE afferents are large-diameter myelinated axons. CLASS (OLDER TERMINOLOGY) DIAMETER CONDUCTION VELOCITY MODALITIES la (Aa) (myelinated) 12-20 urn 70-100 m/sec Proprioception (muscle spindles) lb (Aa) (myelinated) 12-20 urn 70-100 m/sec Proprioception (Golgi tendon organs) II (A|3) (myelinated) 5-12 urn 30-70 m/sec Touch and pressure from skin; proprioception from muscle spindles III (A5) (myelinated) 2-5 urn 10-30 m/sec Pain and temperature; sharp sensation; joint and muscle pain sensation IV (C, unmyelinated) 0.5-2.0 urn 0.5-2.0 m/sec Pain, temperature No need to know it in detail (just to get some idea about the principles © ). The same applies to the previous table. UNI ED According to : Misulis KE. CHAPTER 30 - Sensory Abnormalities of the Limbs, Trunk, and Face. In Bradley WG, Daroff RB 7 Fenichel GM, Jankovic J. Neurology in Clinical Practice, 5th ed. London: Elsevier 2008. - Sensory afferents pass through the dorsal root ganglia (1st sensory neurons) - The contiue on to the dorsal horn of the spinal cord - The give rise to two major ascending pathways: - The POSTERIOR COLUMNS (serving large-fiber modalities, i.e. discriminative touch, vibration, and proprioception) - these axons pass through the dorsal horn without svnapsing and ascend in the ipsilateral dorsal columns to the cervicomedullarv junction, where axons from the leg synapse in the nucleus gracilis (and from the arms in the nucleus cuneatus) and the second-order sensory neurons cross and ascend in the contralateral medial lemniscus - The ANTEROLATERAL SYSTEM (serving small-fiber modalities primarily, i.e. thermal sensation + nociception + affective touch) - These axons synapse in the dorsal horns, and the second-order sensory neurons cross in the anterior 8 white commissure of the spinal cord to ascend in the contralateral spinothalamic tract. SENSORY PATHWAYS Thalamus Medial leminiscus Nucleus gracilis Nucleus cuneatus Fasciculus gracilis Fasciculus cuneatus Dorsal root ganglion Fine touch and proprioception sensations from right side of body Lateral spinothalamic tract Dorsal root ganglion Pain and temperature sensations from right side of body Source: Wikipedia: https://upload.wikimedia.org /wikipedia/commons/e/ee/1 417_Ascending_Pathways_ of_Spinal_Cord.jpg Dorsal column system Spinothalamic tract SENSORY PATHWAY Medulla oblongata Thalamus l~l 1st order neurones l~l 2nd order neurones □ 3rd order neurones Nucleus f ^-"'^cuneatus Nucleus gracilis DORSAL COLUMNS/ MEDIAL LEMNISCUS Lower limb Upper limb Medulla oblongata TeachMeAnatomy Thalamus □ 1st order neurones f~l 2nd order neurones □ 3rd order neurones Nucleus cuneatus Nucleus gracilis Lower limb Upper limb -^^^ Each the pathway consists from 3 sensory neurons connected in series 1 st in the dorsal root ganglia 2nd in the ipsilateral dorsal horn (anterolateral system) or ipsilateral nucleus gracilis/cuneatus (DCLM system) 3rd in thalamus with cortical projection into the postcentral gyrus ANTEROLATERAL SYSTEM/ SPINOTHALAMIC TRACTS Source: h Hps ://teach m ean atomy. i nfo/neu r oanatomy/pathways/ascendi ng -tracts-sensory/ UNI ED SPINAL SENSORY PATHWAY - SOMATOTOPIC ORGANISATION of both pathway - DIFFERENT SENSORY MODALITIES conducted separately propriocepcel Gracilis fasciculus Cuneatus fasciculus Posterior columns (vibration and proprioception) Leg Lower trunk Upper trunk Arm Neck Occiput Anterolateral system (pain and temperature) dotyk Neck Arm 10 Trunk Source: Ambler Z, Bednařík J, Růžička E. Clinical Neurology - General Part. Praha: Triton 2004. Leg https://accessphvsiotherapy.mhmedicalxom print.html THALAMOCORTICAL PART OF THE PATHWAY In the THALAMUS: the ventroposterior complex is the main somesthetic receiving area and includes the ventroposterior lateral nucleus, which receives information from the body, and the ventroposterior medial nucleus, which receives sensory input from the head and face. - Projections are to the primary somatosensory cortex on the postcentral gyrus. The posterior nuclear group receives nociceptive input from the spinothalamic tract and projects mainly to the secondary somesthetic region on the inner aspect of the postcentral gyrus, adjacent to the insula. 'S3 z malik^^ prstenik^^ prostředník^^ PRIMARY SOMATOSENSORY CORTEX ON THE POSTCENTRAL GYRUS - SOMATOTOPIC ORGANISATION (The mapping of the cortex follows the homunculus) zuby,dásně intra-abdominálně V1 S 8 cervical, S 12 thoracic, f ¥. \ ? s\ /3i \ \ / : 4A S 5 lumbar, \i\ '. r5 \ V--\Thir.c5 V-J / 6 ( S 5 sacral, and XV -'i--M C6 ...8 .. \ -. 9 S 1 coccygeal cJ spinal nerves. /\:C7 '•••I? /': V. I \L1*| I '"■ '• V •'r2 \te • \\ V\v \ !S3; VceV'i A DERMATOME is an area of skin that is mainly supplied by afferent nerve fibers from a single dorsal root of spinal nerve/ single spinal segment. BASIC ANATOMY: DERMATOMES S3 It's sufficient to know the most important ones (C5-8 and L2-S2) + the very basic knowledge of the others ©. Ventral rami, spina Genitofemoral Lateral femoral cutaneous BASIC ANATOMY: CUTANEOUS FIELDS OF PERIHPERAL NERVES NERVE SUPPLY OF THE HUMAN ARM AND LEG cutaneous Superficial peroneal Upper lateral brachial cutaneous (axillary] Posterior brachial cutaneous (radfalj and lower lateral brachial cutaneous Lateral antebrachial cutaneous (musculocutaneous] Median Anterior Supraclavicular Medial brachial cutaneous and I ntercosto brachial Medial antebrachial cutaneous Ulnar Upper lateral brachial cutaneous [axillary) Posterior brachial cutaneous trad la IJ and lower lateral brachial cutaneous Posterior antebrachial cutaneous trad la IJ Lateral antebrachial cutaneous tmusculocutaneous) Radial Median Posterior Sural Medial and lateral pla ntar Anterior Iliohypogastric Ilioinguinal Obturator Cutaneous Saphenous Tibial, medial calcanean branches Deep peroneal Medial plantar No need to know it in detail (just to some idea about the principles © ) get Pictures taken from: https://www.msdmanuals.com/professional/ neurologic-disorders/neurologic- examination/how-to-assess-sensation Lateral femoral cutaneous Posterior femoral cutaneous Lateral sural cutaneous Superficial peroneal Tibial, lateral calcanean branches Lateral plantar Posterior UNI ED SENSORY ABNORMITIES 14 - Sensory perception abnormalities are varied. - The pattern of symptoms often is a clue to diagnosis. The most important PATTERNS: - Loss of tactile sensation (numbness)^ ___________1__-S^EGA7\VE SYMPTOMS (relatively late) - Sensory ataxia--- " Neur°Pathic Pain---POSITIVE SYMPTOMS (usually earlier) - Dysesthesia and paresthesia PARTICULAR PATTERNS MIGHT BE MIXED OR SEPARATE MUNI ED SENSORY SYMPTOMS - NUMBNESS - NUMBNESS IS THE LOSS OF SENSATION, usually manifested as decreased sensory discrimination and elevated sensory threshold; - It's a negative symptom - Numbness may involve the 3 major sensory modalities to the same or different degrees: (1) Light touch (2) Pain and temperature sensation (3) Position and vibration sensation - !!! Patients often use the term numbness to mean a variety of other symptoms: weakness (and vice versa); positive sensory symptoms, such as dysesthesia and paresthesia. - OTHER TEMS used to describe decreased sensory perception: - HYPESTHESIA = a partial loss of sensitivity to the stimuli of a certain sensory modality (tTT) - ANESTHESIA = failure to perceive any sensory stimulus of a certain sensory modality (tTT) 15 SYMPTOMS - SENSORY ATAXIA - SENSORY ATAXIA is the difficulty in coordination of a limb that results from loss of sensory input, particularly proprioceptive input. - is distinguished from cerebellar ataxia by the presence of near-normal coordination when the movement is visually observed by the patient, but marked worsening of coordination when the eves are shut. 16 - Patients complain of loss of balance in the dark, typically when closing their eyes in the shower or removing clothing over the head. - Objectively, patients with sensory ataxia demonstrate: - pseudoathetosis (abnormal writhing movements, usually of the fingers, caused by a failure of the proprioception). - posmve Romb^s s!qn m rapid worsening „he„ the eyes are shut, MUNI SYMPTOMS - DYSESTHESIA, PARESTHESIA - PARESTHESIA = an abnormal sensation, whether spontaneous or evoked, which is NOT UNPLEASANT. - DYSESTHESIA = an UNPLEASANT abnormal sensation, whether spontaneous or evoked. - Feeling of tingling or formication in both of them - The borderline may present some difficulties when it comes to deciding as to whether a sensation is pleasant or unpleasant. - It should always be specified whether the sensations are spontaneous or evoked in both the cases - !!! Some people prefere the use of one term (paresthesia) to indicate spontaneous sensations and the other (dysesthesia) to refer to evoked sensations, but such airi |\/| U IM I 17 approache is currently not favored (IASP). urn SYMPTOMS - HYPERALGESIA, ALLODYNIA - SPECIAL CASES OF DYSESTHESIA include hyperalgesia and allodynia. - ALLODYNIA - Pain due to a stimulus that does not normally provoke pain. - Alio means "other" in Greek and is a common prefix for medical conditions that diverge from the expected. Odynia is derived from the Greek word "odune" or "odyne". - the stimulus and the response are in different modes (modalities) - HYPERALGESIA = Increased pain from a stimulus that normally provokes pain. - = reflects increased pain on suprathreshold stimulation. - the stimulus and the response are in the same mode (modality) - can be plotted with overlap along the same continuum of physical intensity in certain circumstances, for example, with pressure or temperature. SYMPTOMS - NEUROPATHIC PAIN caused by a lesion or disease of the somatosensory nervous system (central or peripheral) a clinical description (and not a diagnosis) lesion or disease has to be confirmed by imaging, neurophysiology, biopsies, lab tests... or a medical history of obvious trauma Character: prickling (pins and needles) + shock-like, shooting + burning sensations Usually accompanied by persistent tingling and/or numbness Increased at rest and during the night, usually decreased during the movement May occur spontaneously or with stimulus (allodynia, hyperalgesia) Continuous or episodic or both Mechanisms: Related to spontaneous activity of sensory axons + cross-talk (ephaptic transmission) between damaged axons (allows an action potential in one nerve fiber to be abnormally transmitted to an adjacent nerve fiber) + central (or peripheral) sensitisation Elicited when sensory axons or cell bodies are damaged, not related to damage in innervated tissue LEVEL OF LESION FEATURES AND LOCATION OF SENSORY LOSS Cortical Sensorv loss in contralateral bodv, restricted to the portion of the homunculus affected by the lesion; if the entire side is affected (with large lesions), either the face and arm or the leg tends to be affected to a greater extent Internal capsule Sensorv svmptoms in contralateral bodv, which usuallv involve head, arm, and lea to an eaual extent; motor findinas common, althouah not alwavs present Thalamus Sensorv svmptoms in contralateral bodv includinq head and mav split the midline; sensorv loss without weakness hiqhlv suqqestive of lesion here Spinal transection Sensorv loss at or below a seamental level, which mav be sliqhtlv different for each side; motor examination also key for localization Spinal hemisection (Brown-Sequard) Sensory loss ipsilateral for vibration and proprioception (dorsal columns), contralateral for pain and temperature (spinothalamic tract) Nerve root Sensorv svmptoms follow a dermatomal distribution Plexus Sensorv svmptoms span two or more adjacent root distributions, corresponding to the anatomy of the plexus divisions Peripheral nerve Distribution follows peripheral nerve anatomy or involves nerves symmetrically SENSORY LOCALISATION A) Hemisensory loss as a result of a contralateral hemispheric lesion. B) Hemisensory because of a contralateral thalamic lesion C) Midthoracic spinal sensory level (spinal transsection) D) Dissociated sensory loss to pain and temperature as a result of syringomyelia. E) Distal, symmetrical sensory loss because of peripheral neuropathy. F) Crossed spinothalamic loss on one side with posterior column loss on the opposite side because of Brown-Sequard syndrome (spinal hemisection) G) Dermatomal sensory loss because of cervical radiculopathy (C6) H) Peripheral nerve lesion (peroneal). H ,, B| T Modified from: https://www.sciencedirect.com/topics/medicine-and-dentistry/dissociated-sensory-loss MUNI MED SENSORY EXAMINATION AND HISTORY ALWAYS ASK the patient about the distribution of sensory symptoms/pain, pain intensity (NRS, VAS, FPS...), duration, mode Of onset. Clinical course (relapsing remitting? stable? progressive? short attacs?) + what relieves the symptoms/ makes them worse? Patients frequently dorTt describe the problems using apropriate words (confuse hypoesthesia with weakness, impaired proprioception causing the instability when walkig may describe as „vertigo"...)!M; patients may not be aware of any sensory deficit (vibration, proprioception...); the patient may complain of sensory loss, but examination fails to reveal a sensory deficit (particularly frequent in the loss of small-fiber functions). 0123456789 10 I—I—I—r t—i—I—I—I—I NoPiin Mild MotwMt Sevtn Very Sen™ pj3S? ^f^j Remind the subjective nature of the clinical examination; 0 1"3 4"6 7'9 10 the subject must be conscious and cooperating (sensory deficits can't be evaluated in unconscious individuals, in case of aphasia, severe cognitive decline and/or non-cooperative patients); inconsistency in the patient's responses is common (and doesn't automatically mean malingering). SENSORY EXAMINATION - PRINCIPLES - Be aware of aphasia, cognitive decline, loss of consciousness (delirium) or fatigue - The evaluation of the sensory system is completed with the patient lying supine - Testing should not occur over closing - No visual control during the testing (eves closed) - It's thus very important that you first inform the patient about the purpose of each test, what you plan to do and how he/she should respond to each stimulus. - In each of the modalities, start with basic evaluation of whole the body surface - Testing should compare the right and the left side (even if both sides are affected) - Testing should compare distal to proximal areas (or other „probably affected (limbs) and „probably non-affected" (face) areas) MUNI MED SENSORY EXAMINATION - PRINCIPLES - The patterns and pace of the testing should be varied, so the patients cannot reognize a pattern and respond correctly due to an educated guess - The further extent of testing depends on the results of such a basic evaluation and on the PRESENCE/ ABSENCE of SENSORY SYMPTOMS - If somatosensory loss is present, attempt to map the area with distinct boundaries to best determine the type and extent of the lesion/condition/disease (does the distribution correspond to particular peripheral nerve/ root/ plexus/ spinal level/ hemisecion/ distal distribution related to polyneuropathies?) - = try to find the transition between the regions with normal and abnormal perception of particular modality (touch, pinprick...) (see next slide) - If possible, mark the areas of somatosensory abnormities in the body diagramttt MUNI MED SENSORY EXAMINATION - TRANSITION LINE - To find the transition between the regions with normal and abnormal perception, the testing should be performed repeatedly, perpendicular to the expected transition line - In spinal lesions, the SENSORY LEVEL is determined by performing an examination of both pin prick (sharp/dull discrimination) and light touch sensation within each of the 28 dermatomes on each side of the body (right and left) (sensory level is the most caudal, normally innervated dermatome) (may be different for the right and left side, Kirshblum et al. 2011) - In hemisensorv distribution, SHARP MIDLINE TRANSITION IS ATYPICAL (it s moved 2-4 cm to the affected side due to the transmedian overlaping of cutaneous innervation) (peripheral nerves cross the midline and the innervation overlaps in all the regions - head/neck, thorax/abdomen, back, perineum, and genitalia) (Capeketai.2015). MUNI 25 Kirshblum SC et al International standards for neurological classification of spinal cord injury. J Spinal Cord Med 2011; 34(6): 535-54. II fl P R Capek S, Tubbs RS, Spinner RJ. Do cutaneous nerves cross the midline? Clin Anat 2015;28(1):96-100. IVI I- U SENSORY MODALITIES TESTED - LARGE-FIBER (DCLM-RELATED) MODALITIES - Vibration - Deep presure - Discriminative touch (stereognosis, graphesthesia, 2-point discrimination) Proprioception: - statesthesia (joint position sense) - kinaesthesia (the sense of movement and dynamic position sense) - SMALL-FIBER (SPINOTHALAMIC TRACT - RELATED) MODALITIES - Pain (nociception) (sharp mechanical pain - pinprick, thermal pain...) - Temperature (warm + cold) - Non-discriminative (affective) touch - SENSORY THRESHOLD = the minimum stimulus intensity detected by a subject MUNI MED COTTON SWAB AND BRUSH LIGHT TOUCH use a cotton wisp, cotton swab or brush (or possibly your fingers) apply a gentle touch (dynamic tactile stimuli are always perceived better than the static ones!!) ask the patient to close their eves and report "yes" every time they perceive the stimulus. Another possibility is to alternate touching the patient with the needle and the swab/ brush at intervals of roughly 5 seconds. Instruct the patient to tell the physician if they notice a difference in the strength of sensation on each side of their body. Use of dynamic stimuli also tests for dynamic mechanical allodvnia For quantitative touch assessment, set of calibrated monofilaments can be used (by bending, each of them produces precisely defined mild pressure/touch on the skin). Most frequently, the 10 g filament is used as a calibrated stimulus (see next slide). UNI ED use a disposable pin or specific devices: Neuropen (Owen Mumford) is a pocket-size device combining: - Calibrated Neurotic test (40 g) assesses reduced sensation to sharpness/pain in small nerve fibres. - Calibrated monofilament test (10 g) assesses protective touch/pressure sensation in large nerve fibres - Use both devices randomly in any region A set of calibrated pinpricks allows detained quantitative testing (mechanical pain threshold can be established) In any device used, ask the patient to close his/her eves and report whether he/she feels the stimulus sharp or dull. SHARP PAIN CALIBRATED PINPRICK DEEP PRESSURE, PRESSURE PAIN - Mainly large fibers, DCLM system - Blunt pressure applied on the muscle mass (thenar eminence....) - e.g. by pressure gauge device -allows quantification of the pressure pain threshold - or just by the pressure of examinator's thumb TEMPERATURE (WARM AND COLD) - Small fibers, anterolateral (spinothalamic) tracts - TESTING OPTIONS: - random use of the test tubes filled with hot (115 to 120 °F, i.e. 46 to 49 °C) or cold (40 to 50 °F, i.e. 5 to 10 °C) water. - a cold vibration fork (if needed, it can be cooled by running it under cold water) and ask the patient if they perceive the vibration fork as cold. - a TipTherm (Bailey) device - made of special polymer and metal alloys - the polymer side feels warmer and the metal alloy side cooler due to the thermal conductivity property of the materials) - use both sides randomly and always ask the patient if he/she perceives the stimulus as warm or cold - thermal threshold testing - a quantitative sensory testing method -a thermode with the temperature increasing/decreasing from neutral temperature of 32 °C. Warm/ cold thermal detection threshold (and hot/ cold thermal pain threshold) can be established. PROPRIOCEPTION (joint position sense) - Large fibers, DCLM tracts - tested by holding the most distal joint of a digit and moving it slightly up or down. Make certain to hold the digit on its sides, because holding the top or bottom provides the patient with pressure cues which make this test invalid. First, demonstrate the test with the patient watching so they understand what is wanted then perform the test with their eves closed. The patient should be able to detect 1 degree of movement of a finger and 2-3 degrees of movement of a toe. If the patient can't accurately detect the distal movement then progressively test a more proximal joint until they can identify the movement correctly. - Impaired proprioception also causes: - Loss of ability to walk with eves closed - positive Romberg s sign - pseudoathetosis (abnormal writhing movements, usually of the fingers) SENSE OF VIBRATION (PALLESTHESIA) - large fibers, DCLM system - use an oscilating 128 hertz tunning fork - place over bony prominencies (radial styloid process, tuberosity of the tibia, medial or lateral ankle, the distal phalanx of the index finger or large toe). - ask the patient to report whether thev feel vibration sense and then to report when it stops in order to assess the minimal threshold to perceive the stimulus. - compare to your own extremities or use a calibrated tunning fork and record the number from the scale JAMAR STEREOGNOSIS KIT (Performance DISCRIMINATION -STEREOGNOSIS - large fibers, DCLM system - explain to the patient that you will be placing an item in their hand which thev should then manipulate and identify with their eves closed. - stimuli include different coins, a key, a safety pin, a paper clip, a coin, etc. - Specific kits are available containing a set of objects for the purpose of stereognosis 33 testing (—►—►—►) DISCRIMINATION - GRAPHESTHESIA - explain to the patient that vou will be drawing a number in the palm of their hand or other region - explain to the patient what is up and down, the distal side is usually up as this is a typical orientation of the palm. - demonstrate with eyes open. - ask the patient to close their eves. - with a blunt item such as your fingertip draw a number across the palm and ask the patient to 34 identify it- Large fibers, DCLM system MUNI MED 2 POINT DISCRIMINATION - large fibers, DCLM system - use either calipers or a opened paper clip with two parallel ends or Webers compass - demonstrate to the patient with eyes open by applying either one or two points of the stimulus to the fingerpad. - ask the patient to close their eves. - deliver the stimulus and ask the patient to report whether they feel one or two points. - Normal response: normal values over the fingerpads are 2-4 mm. MUNI MED TACTILE (SENSORY)EXTINCTION (DOUBLE SIMULTANEOUS STIMULI) - EXTINCTION = neurological sign, impaired ability to perceive multiple stimuli of the same type simultaneously. Usually caused by a lesions on one side of the brain. Affected patients lack the awareness in the contralesional side of space (towards the left side space following a right lesion) and a loss of exploratory search and other actions normally directed toward that side. - with eyes open demonstrate to the patient that you will touch them on the left side, the right side or both. - this should only be done if the patient can perceive a unilateral stimulus (i.e. if there is loss of pain and temperature or light touch on one side, there would be no point assessing extinction). - have the patient close their eves and as you deliver a gentle touch, report whether thev feel it on the left side, right side or both sides. M U FUNCTIONAL SENSORY LOSS The clinical presentations SUGGESTING FUNCTIONAL SENSORY LOSS include the following: Sensory loss exactly splitting the midline, with a minimal transition zone Circumferential sensory loss around the body or an extremity Failure to perceive vibration with a precise demarcation Loss of vision or hearing on the same side of the body as for the cutaneous sensory deficit Total anesthesia 37 MUNI MED MENINGEAL SYNDROME MENINGEAL SYNDROME - DEFINITION - Meningeal syndrome groups together symptoms connected with any pathological irritation of the meningeal envelopes and the cerebrospinal fluid. - It accompanies biological changes in these components of the nervous system: - Meningeal infammation (meningitis, meningoencephalitis) - Meningeal hemorrhage (subarachnoid hemorrhage) - Rarely meningeal carcinomatosis Very rarely exogenous intoxication - A set of typical symptoms and signs - The signs are mainly associated with a reflectory tonic contraction of skeletal muscles (mainly paraspinal muscles, cervical extensors and hip and knee joint flexors) 39 _ The signs may be absent in infants, elderly patients or patients in coma M E D ^ MENINGEAL SYNDROME - SIGNS The most important symptoms: headache, nauzea + vomiting, photo/ phonophobia. HEADACHE - the most common, most consistent and earliest symptom. - a consequence of either intracranial hypertension or inflammation of structures of the cranial base. - usually very intense, violent, diffuse (sometimes predominantly frontal) and constant (with paroxysms). Can prevent sleep. It is not relieved by the usual analgesics - It is typically worsened by: - noise (phonophobia) - light (photophobia) - coughing - abdominal pressure „ T ri ■ r .1 I MUNI 40 _ flexion of the neck. R/l E D MENINGEAL SYNDROME - SYMPTOMS NAUZEA and VOMITING - Frequent symptoms - Inconsistently, so called „cerebral' vomiting can be present - it is projectile, unrelated to meals, frequently spontaneous or occurring when the patient changes position. PHOTO- and PHONOPHOBIA Quite common, particularly in pronounced clinical symptoms CONSTIPATION - It used to be mentioned as the third element in the classic meningeal triad (headache, vomiting and constipation). 41 - It is a rather irregular symptom and of limited practical impact MUNI MENINGEAL SYNDROME - SIGNS MENINGEAL STIFFNESS - = a contracture of the paravertebral muscles - a defense against the secondary pain stemming from inflammation of the meninges. - Painful and permanent - In pronounced clinical pictures, it presents with the subject lying down, curled up with his or her back to the light, head back, the patient's entire spine is hyperextended, and extremities half-bent - an extreme posture called opisthotonus (chasing-dog position). - Frequenty, there is an extreme neck stiffness (called nuchal rigidity); - all attempts to flex the head provoke insurmountable and painful resistance. - rotational and side-to-side movements are possible, but aggravate the headache. MENINGEAL STIFFNESS CLINICAL TESTS - Maneuvers that confirm meningeal stiffness. - KERNIG'S SIGN - The patient resists full extension of the knee when the knee and hip are first flexed (patient's left leg), although the knee extends normally if the hip is extended (patient's right leg). - BRUDZINSKI'S SIGN - The flexion of the patient's neck causes the hips and knees to flex, pulling both legs up toward the chest. - Many people with meningitis don't have the none of 43these tests positive (Brudzinski, Kernig, nuchal rigidity....)- nuchal rigidity O + 0 + t Brudzinski's sign spine sign tripod sign (Amoss' sign) Keen ] % ip Difficulty luty extending knee it hip tloxod l'll;c.'I".M '.i .1 Neck flexion causes knee flexion MENINGEAL STIFFNESS: ACCOMPANYING SIGNS - slowing of the cardiac rhythm - cutaneous hypersensitivity - the meningeal mark of Trousseau: if a line is traced on the skin with a fingernail, a mark appears; initially white, it reddens and then slowly disappears - fever, often elevated and dissociated from the pulse. - In severe cases the following are seen: - neurological signs caused by irritation of the underlying nervous system: epileptic seizures, limb paresis, paresis of the cranial nerves (notably oculomotor paralysis), psychiatric disorders. MUNI 44 MED MAIN SOURCE OF INFORMATION - Misulis KE. CHAPTER 30 - Sensory Abnormalities of the Limbs, Trunk, and Face. In Bradley WG, Daroff RB, Fenichel GM, Jankovic J. Neurology in Clinical Practice, 5th ed. London: Elsevier 2008. - https://www.iasp-pain.org/Education/Content.aspx?ltemNumber=1698 - https://www.sciencedirect.com/topics/medicine-and-dentistrv/meninqism - Some of the pictures were taken from: Ambler Z, Bednařík J, Růžička E. Clinical Neurology - General Part. Praha: Triton 2004. 45 MUNI MED