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)