Clinical neurophysiologyEND-Techniques

Case studies

Diabetic neuropathy

Diabetic neuropathies are a family of nerve disorders caused by diabetes

Symptoms are pain, tingling, or numbness, loss of feeling in the hands, arms, feet, and legs.

Nerve problems can occur in every organ system, including the digestive tract, heart, and sex organs

Causes of diabetic neuropathies

High blood glucose Long duration of diabetes Low levels of insulin Neurovascular factors Autoimmune factors that cause inflammation in

nerves Smoking or alcohol use

symptoms

Several times urination, especially night time Numbness, tingling, or pain in the feet. Numbness, tingling, or pain in the toes, feet, legs, hands, arms, and

fingers Wasting of the muscles of the feet or hands Indigestion, nausea, or vomiting Diarrhea or constipation Dizziness or faintness due to a drop in blood pressure after standing

or sitting up Problems with urination Erectile dysfunction in men or vaginal dryness in women Weakness

Types of diabetic neuropathy

Peripheral: pain or loss of feeling in the toes, feet, legs, hands, and arms.

Autonomic: digestion, bowel and bladder function, sexual response, and perspiration, lungs, eyes

heart and blood pressure Proximal: pain in the thighs, hips, or buttocks Focal: sudden weakness of one nerve or a group

of nerves, causing muscle weakness or pain

Principle of axonal degeneration:dying back hypothesis

Nerve conduction studies or electromyography

Hand motor median nerve:distal and proximal

motor+F-response Ulnar nerve:proximal and distal

motor+F-response (make sure the patient does not have CTS). Look contra-lateral.

Leg motor: Tibial nerve:distal and proximal motor+ F-response Peroneal nerve: distal and proximal motor

Sensory Hand sensory: median and ulnar nerve Leg sensory: sural nerve

Ulnar nerve entrapment

F-response

When a peripheral motor nerve is

electrically stimulated, impulses

travel orthodromically toward the

muscle and antidromically

toward the spinal cord.

The antidromic impulses are

capable of discharging alpha

motoneurons that then elicit

recurrent orthodromic impulses

Axonal reflex

In normal conditions, they are only seen in tibial nerve.

In earlier GBS,IDD can be seen.

They are also called IDD(Intermediate Double Dischares) or M-satellites.

Fine-fibers and autonomic neuropathy testing Heat testing Cold testing SSR R-R interval Orthostatic Q-Sweat-postganglionic sympathetic

sudomotor axon

Psychophysic

VEP SSEP LEP(Laser Evoked Potential) BAEP

Charcot-Marie-Tooth (CMT) Hereditary Motor and

Sensory Neuropathies The legs showed mild atrophy of the anterior tibialis and peroneal muscles

Hypertrophic polyneuropathy. The most likely diagnosis was chronic inflammatory demyelinating polyneuropathy

Her nerve conduction velocities (NCV) were 24.7m/s in both median and ulnar

nerves without multifocal blocks

Motor NCV of the right peroneal nerve was 14.7m/s; the motor NCV of the left ulnar nerve was 16.9m/s; and the motor NCV of the right median nerve was 21.2m/s

Lack of conduction blocks argued against chronic inflammatory demyelinating polyneuropathy (CIDP)

Based on the molecular studies and electrophysiological examination, the diagnosis of Charcot-Marie-Tooth type 1A polyneuropathy was made.

Pes cavus Toeswalking

GBS

Guillain-Barré syndrome is a disorder in which the body's immune system attacks part of the peripheral nervous system

Usually Guillain-Barré occurs a few days or weeks after the patient has had symptoms of a respiratory or gastrointestinal viral infection.

Nerve conduction velocity (NCV) test can give a doctor clues to aid the diagnosis

Multiple Motor Neuropathy

Multifocal motor neuropathy (MMN) with conduction block

Immune-mediated demyelinating neuropathy with slowly progressive weakness, fasciculations, and cramping, without significant sensory involvement

It may resemble amyotrophic lateral sclerosis (ALS) with predominant lower motor neuron involvement, but muscle atrophy and more rapid progression are lacking

IV immunoglobulin (IVIG) or cyclophosphamide improve the

patient´s condition in MMN but not in ALS patients

Electrodiagnostic studies demonstrate the presence of both demyelinating and axonal injury.

Clinical and electrodiagnostic criteria for the diagnosis of MMN include the following:

Definite MMN Weakness without objective sensory loss in the distribution

of 2 or more nerves is present. Definite conduction block is present in 2 or more motor

nerves outside of common entrapment sites.

Sensory nerve conduction velocity is normal across the segments with demonstrated motor conduction block.

Results are normal for sensory nerve conduction studies on all tested nerves, with a minimum of 3 nerves tested.

Upper motor neuron signs, including spasticity, clonus, extensor plantar response, and pseudobulbar palsy are absent

Conduction block

Absence of F-response

Conduction block outside of common entrapment sites.

The conduction block should not be an entrapment

EMG: Normal activity Fibrilation

Insertion activity: normal Fibrilation: positive sharp waves

Muscle physiology

Motor neuronDegenerative motor neuron