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NUMBNESS AND TINGLING
Neurology for the Non Neurologist
Marcus Neuroscience Institute
Update 2019
WHAT DO PATIENTS SAY?
• If a patient complains of a “numb” body part,
it may ironically mean lack of strength.
• It is essential to then ask,
• “Are you able to move the body part in question?”
• This will help localize the lesion in the nervous system.
• Lack of sensation seems less threatening than paralysis but may be serious.
• Stroke patients when faced with a numb body part are unalarmed and may fail to seek help escaping the therapeutic window.
• Sensory loss may be from a neoplasm in the sensory cortex or along a nerve.
WHAT DO PATIENTS SAY?
• Patients believe numbness means “lack of circulation”. Two similar scenarios:
• “My hand feel asleep.”
• They shake their hand to “restore circulation”.
• Median nerve compressed by flexed wrist whilst sleeping.
• “My leg feel asleep.”
• Shake the leg until sensation and strength returns.
• Sciatic nerve compression against a hard chair edge
• Unaware that moving the limb decompresses a nerve to allow it to recover.
LOCALIZATION
• Is numbness from the central nervous system or peripheral nervous system?
• Either location may be life threatening.
• Brainstem stroke.
• Acute polyradiculoneuropathy(Guillain Barre).
• Both may progress to quadriparesis and respiratory compromise.
• In the emergency department, diagnosis is a critical.
• MRI and Reflex hammer are important.
•Central Nervous System
• Cerebral Cortex
• Basal ganglion
• Brainstem
• Spinal Cord
•Peripheral Nervous System
• Spinal Roots
• Plexus
• brachial or lumbar
• Peripheral Nerves
• Neuromuscular Junction
• Muscles
•Visceral Nervous System
• Sympathetic
• Parasympathetic
SUBDIVISIONS OF THE NERVOUS SYSTEM
On which floor will I spend my time?
Neurology
Department
Store
THE TENDON REFLEX
• Examiner must be confident that the absence of a reflex is not artifact.
• Key clinical situations where reflexology is diagnostic.
• Disappearing reflexes in GBS (diagnostic and for tracking progression)
• Absent biceps reflex with thumb paresthesia (radiculopathy vs CTS)
• Absent Achilles reflex with a foot drop (partial sciatic verse peroneal neuropathy)
• Peripheral neuropathy pattern vs radicular pattern (bilateral vs. unilateral loss of ankle
jerk)
• Hyperreflexia with upper motor neuron weakness (stroke, ALS, tumor)
• Decreased or increased reflexes showing metabolic state (calcium, magnesium)
PRIMARY SENSORY CORTEX (POST CENTRAL GYRUS)
INFLOW
1
2
3
Anatomy determines clinical signs
•Three neuron system organized somatotopically. • Dorsal Column
• Large fiber system (waxed Lexus)
• Proprioception and vibration
• Cross at medullary level
• Spinothalamic
• Small fiber system (unpainted KIA)
• Pain and temperature
• Cross at spinal level (through Kissimee)
Magic Kingdom
Kim, J. S. Neurology 2007;68:174-180
CORTICAL REPRESENTATION OF PARESTHESIA
Perioral or Finger Numbness
GBM PRESENTING AS NUMBNESS
T1Flair
C+
T1 Flair
C+
T1Flair C-
HEMISENSORY LOSS
THALAMUS & VASCULAR SUPPLY
From Stroke Made Simple by permission of the author N. Razack, M.D.,J.D. 2018
POSTERIOR INFERIOR CEREBELLAR (PICA) VERTEBRAL ARTERY STROKE
• Glossopharyngeal and vagal fibers • Dysphagia, hoarseness, ipsilateral paralysis of vocal cord; ipsilateral loss of
pharyngeal reflex, tachycardia
• Vestibular nuclei • Vertigo, nystagmus, lateropulsion
• Descending tract and nucleus of fifth nerve • Ipsilateral facial numbness
• Spinothalamic tract • Contralateral body numbness
• Solitary nucleus and tract • Taste loss on ipsilateral half of tongue posteriorly
Adapted from Merritt’s Neurology From Ovid Full Text. NovaSoutheastern Institutional Subscription
MNI 8/2018
CROSSED SENSORY LOSS
Pain and Temperature
Lateral Medullary Syndrome
T-4 nipple
T-10 umbilicus
L-5 big toe
S-1 little toe
SPINAL CORD SENSORY LEVELS
Netter atlas
Sacral Sparing in
Central Cord lesion
PARESTHESIA
• Thirty y/o woman presents with 2 week
history (10/2018) of right leg numbness,
thoracic dysesthesia that spread to the
left foot then upward to the T4 level
• Mild urinary urgency
• Sent to emergency room for admission
• ER physician was convinced she had a
conversion reaction.
• She had Multiple Sclerosis.
Netter Atlas
CENTRAL CORD SYNDROME: SYRINGOMYELIA
Shawl Hypalgesia
Sagástegui-Rodríguez, J. A. et. al. N Engl J Med 2002;346:1e
CENTRAL CORD SYNDROME: SYRINGOMYELIA
24 year old man with 3 years of progressive muscle wasting and sensory loss in his arms, dysphonia and dysphagia.
Netter Atlas
VITAMIN B12 DEFICIENCY
Paresthesia, loss of vibratory and position sense and glossitis
myelopathy
Netter Atlas
ROMBERGISM /SENSORY ATAXIA
Netter Atlas
VITAMIN B12 DEFICIENCY
Scherer, K. N Engl J Med 2003;348:2208
56-year-old woman with 4 months of progressive cognitive decline, weakness, incoordination, and gait disturbance
SUBACUTE COMBINED DEGENERATION
VITAMIN B12 DEFICIENCY
• Encephalopathy
• Dementia and depression
• Myelopathy (lower cervical first)
• Peripheral neuropathy
• Optic neuropathy
• May have acute deficiency if borderline and exposed to NO either medically or recreationally
Conus Medullaris
Cauda Equina
Central Disc Herniation:
•Saddle numbness
•Bowel/bladder dysfunction
•Neurosurgical emergency •Non-somatic nerves sensitive to pressure
and may not recover
CAUDA EQUINA SYNDROME
RADICULOPATHY
• Shingles (herpes zoster)
• Anesthesia dolorosa
• Diabetes mellitus
• Thoraco-abdominal radiculopathy
BRACHIAL PLEXOPATHY
Parsonage Turner Syndrome
Pain, paresthesia
along with weakness
LENGTH DEPENDENT PERIPHERAL NEUROPATHY
Vibratory loss
Foot Drop
Common Length Dependent Neuropathy
PERIPHERAL NEUROPATHY
Sensory Ataxia
Absent ankle
jerk
Cause of
unexplained
dizziness and
falls
MONONEURITIS MULTIPLEX
25 y/o woman
presented to BRRH ED
with numbness in left sup
peroneal, right med cut n of
forearm and right Ulnar n
distribution underlying
MCTD and vasculitis 8/2018
NEUROPATHY EXAMINATION
• Pattern of weakness
• Distribution and character of sensory loss
• Nerve enlargement
Above ulnar groove, Greater auricular nerve,
Peroneal Nerve at the fibular head
• Skeletal exam to exclude foot deformities
INHERITED PERIPHERAL NEUROPATHY
Pes Cavus
CHAMPAGNE GLASS ATROPHY
Loss of Medial Gastrocnemius Bulk
FOCAL PERIPHERAL NEUROPATHY WITH SENSORY COMPLAINTS
• Median Nerve at the wrist
• Carpal tunnel syndrome
• Ulnar Nerve at the elbow
• Cubital tunnel syndrome
• Lateral cutaneous nerve of the thigh
• Meralgia paresthetica
CARPAL TUNNEL SYNDROME
• Paresthesia and pain in the wrist, hand and fingers, typically worse at night or on awakening from sleep
• Paresthesia usually present in median distribution, often only at the tips of fingers
• Pain and discomfort may involve the arm, shoulder and scapular
• Weakness of thenar muscle occurs late
CARPAL TUNNEL SYNDROME SIGNS
• Sensory impairment median distribution
• Weakness of abductor pollicis brevis
• Atrophy of thenar eminence (usually late)
CARPAL TUNNEL SYNDROME ETIOLOGY
• Idiopathic
• Reduced space in the carpal tunnel
• Increased susceptibility of nerves to pressure
• Associated conditions
• Hypothyroidism, diabetes mellitus, pregnancy, acromegaly, wrist
fracture, rheumatoid arthritis
COMPUTERS AND CARPAL TUNNEL
• Carpal tunnel syndrome is a common and costly peripheral neuropathy. Occupations requiring repetitive, forceful motions of the hand and wrist may play a role in the development of carpal tunnel syndrome. Computer keyboarding is one such task, and has been associated with upper-extremity musculoskeletal disorder development. The purpose of this study was to determine whether continuous keyboarding can cause acute changes in the median nerve and whether these changes correlate with wrist biomechanics during keyboarding. Methods: A convenience sample of 37 healthy individuals performed a 60-minute typing task. Ultrasound images were collected at baseline, after 30 and 60 min of typing, then after 30 min of rest. Kinematic data were collected during the typing task. Variables of interest were median nerve cross-sectional area, flattening ratio, and swelling ratio at the pisiform; subject characteristics (age, gender, BMI, wrist circumference, typing speed) and wrist joint angles. Findings: Cross-sectional area and swelling ratio increased after 30 and 60 min of typing, and then decreased to baseline after 30 min of rest. Peak ulnar deviation contributed to changes in cross-sectional area after 30 min of typing. Interpretation: Results from this study confirmed a typing task causes changes in the median nerve, and changes are influenced by level of ulnar deviation. Furthermore, changes in the median nerve are present until cessation of the activity. While it is unclear if these changes lead to long-term symptoms or nerve injury, their
existence adds to the evidence of a possible link between carpal tunnel syndrome and keyboarding. Highlights: * Median nerve cross-sectional area and swelling ratio increased after 30 and 60 min of typing. * Responses to typing were greater in those who approached greater peak angles of ulnar deviation. * Nerve size at 60 min reverted to baseline size after 30 min of rest. (C) 2015Elsevier, Inc.
• Clinical Biomechanics. 30(6):546-550, July 2015.
CARPAL TUNNEL SYNDROME
• Differential Diagnosis:
• C6 or C7 radiculopathy
• Always test the biceps reflex
• Investigations
• Nerve Conduction, Electromyography
NERVE CONDUCTION STUDY
8/2018
ELECTROMYOGRAPHY
Fibrillations
10/2015
CARPAL TUNNEL SYNDROME TREATMENT
• Avoidance of precipitating or
aggravating activities with the hand
• Wrist Splint at night
• Local corticosteroid injections
• Surgical decompression
• (even late)