Polyneuropathies

Acute demyelinating polyneuropathy

Guillain-Barre syndrome (GBS) is an acute inflammatory polyneuropathy which manifests as progressive muscle weakness, loss of tendon reflexes and sensory disturbances. Although, this is a rare disease with benign prognosis some patient suffer from severe forms of GBS with long and incomplete remission. According to actual publications 30% of patients suffered GBS have to change their professional and social activities due to persistent neurologic deficiency.

GBS is a most frequent cause of neuromuscular paralysis worldwide. After prevention of poliomyelitis GBS is the most frequent cause of acute peripheral paralysis in Western Europe. Annual incidence of GBS is 1.2-2.3:100000 country by country. The rare forms of GBS like Miller Fisher syndrome are about 0.1/10000/year. There are no current publications stating that GBS incidence is fluctuating comparing it in a long time periods. But simultaneously, some epidemiologic studies shows increased incidence of GBS over a period of last years.

GBS clinically is characterized by fast progressing, bilateral and relatively symmetric paralysis of extremities’ musculature, sometimes accompanied by respiratory muscle paralysis. All symptoms mentioned above starts 1-4 weeks after an infection: in 32% cases it is Campylobacter jejuni, 15% – Cytomegalovirus, rarely by Mycoplasma pneumoniea, EBV, VZV. Usually, paralysis of the musculature evolves gradually. There are reports of GBS after vaccination or surgical procedures. 2 different types of GBS are distinguished by pattern of progression of motor symptoms.

-          Ascending type – paralysis of lower extremities evolves in the begging, later upper extremities and cranial nerves are involved.

-          Descending type – First symptoms are seen in upper extremities and cranial nerves, later progressing to lower extremities.

Firstly, muscle weakness affects only proximal or distal muscle group but later in the course of the disease it spreads to the unaffected muscle group. If pathological process involves thoracic nerves respiratory weakness may evolve and substantially complicate course and prognosis of the disease.

Some patients suffer from cranial nerve lesions. Commonly involved nerves are:

-          n. oculomotorius – paresis of horizontal gaze

-          n. facialis – palpebral ptosis, mouth angle depression

-          n. glossopharyngeus, n. vagus, n. accessories, n. hypoglossus – bulbar syndrome with dysarthria, dysphagia, dysphonia and soft palate paresis are seen

Sensory disturbances in GBS patients are manifested as deep and superficial sensory deficits by “stocking and gloves” type.

Autonomic dysfunction is characterized by rapid fluctuations of blood pressure, orthostatic hypotension or hypertension, arrhythmias, urine retention and paralytic ileus.

Analysis of cerebrospinal liquor

To define diagnosis it’s mandatory to perform a spinal tap. High protein concentration (>0.5 g/l) and normal cell concentration (<10/mm3) in cerebrospinal liquor of the patient is a characteristic sign of GBS. This sign is called albumin-cytological dissociation (ACD). Proteins are elevated due to circulating antibodies in the liquor. ACD reaches its peak about second – third week disease. According to the literature, 25% of patients have ACD at first week but 84% at fourth week (van Doorn, Ruts et al. 2008).

Nerve conduction studies

GBS syndrome is classified to subtypes by neurographic pattern and divided into: AMAN, AMSAN, AIDP

AIDP – acute inflammatory demyelinating polyneuropathy

AMAN – acute motor axonal neuropathy

AMSAN – acute motor and sensory axonal neuropathy

Miller Fisher syndrome – ataxia, areflexia, ophthalmoplegia

Specific therapy

Plasmapheresis

Usually plasmapheresis course is done in 5 procedures by time of 2 weeks, fully changing patient’s plasma about 5 times. Side effects are hypotension, sepsis and complication associated with central venous port (Vucic and davies 1988).

Human immunoglobulin intravenous administration (IVIG)

Human’s polyvalent immunoglobulin G is used in IVIG. 0.4 g/kg/24h 5 day long is a usual course of IVIG. Side effects of IVIG are aseptic meningitis, rash, acute kidney failure, anaphylaxis, blood hyperviscosity syndrome and cerebral infarct.

Other therapeutic options

Corticosteroids

Interfero beta

Prognosis

Most of the patients have a good prognosis for full functional recovery. But 10-20% GBS patients have persistent muscle weakness for about 6 months. For 3-6% of patients’ chronic form of the disease after an acute GBS episode can evolve. Mortality is 5-10%.