Guillain-Barré syndrome

Guillain-Barré syndrome Discuss the pathogenesis and triggering organisms . Describe the clinical features of Guillain-Barré syndrome and the main types. Recognize the complications of the syndrome. List investigations to differentiate it from other causes of muscle weakness. Outline of the treatment modalities.

Post-infectious polyneuropathy Involving mainly motor nerves Sometimes also sensory and autonomic nerves. Affects people of all ages Most patients have a demyelinating neuropathy Primarily axonal degeneration

Usually follows a nonspecific viral infection by about 10 days. Gastrointestinal (especially Campylobacter jejuni, but also Helicobacter pylori) Respiratory tract (especially Mycoplasma pneumoniae) symptoms. Reported following administration of vaccines Rabies Influenza Poliomyelitis (oral) Conjugated meningococcal vaccine (serogroup C).

CLINICAL MANIFESTATIONS Landry ascending paralysis Proximal and distal muscles are involved relatively symmetrically 9% Asymmetry Tendon reflexes are lost, usually early in the course, but are sometimes preserved until later. This variability can cause confusion.

Cases with an abrupt onset The onset: gradual progresses over days or weeks. Cases with an abrupt onset tenderness on palpation and pain in muscles is common in the initial stages. Weakness can progress →inability or refusal to walk → flaccid tetraplegia. Paresthesias: some cases.

Bulbar involvement occurs in about half of cases. Respiratory insufficiency can result. Dysphagia and facial weakness are often impending signs of respiratory failure. Extraocular muscle involvement is rare

Miller-Fisher syndrome Acute external ophthalmoplegia Ataxia Areflexia. Overlaps with Bickerstaff brainstem encephalitis Shares many features with Guillain-Barré syndrome with lower motor neuron involvement

Urinary incontinence or retention of urine: 20% of cases Usually transient

The autonomic nervous system is also involved in some cases. Labiality of blood pressure and cardiac rate Postural hypotension Episodes of profound bradycardia Occasional asystole Cardiovascular monitoring is important.

Classification of Guillain-Barre syndrome and related disorders

DIFFERENTIAL DIAGNOSIS SPINAL CORD LESIONS PERIPHERAL NEUROPATHIES Acute transverse myelitis Epidural abscess Tumors Poliomyelitis Hopkins syndrome Vascular malformations Cord infarction Fibrocartilaginous embolism Cord compression from vertebral subluxation related to congenital abnormalities or trauma Acute disseminated encephalomyelitis Toxic Vincristine Glue sniffing Heavy metal Organophosphate pesticides Infections HIV Diphtheria Lyme disease

DIFFERENTIAL DIAGNOSIS PERIPHERAL NEUROPATHIES NEUROMUSCULAR JUNCTION DISORDERS Inborn errors of metabolism Leigh disease Tangier disease Porphyria Critical illness: polyneuropathy/myopathy Tick paralysis Myasthenia gravis Botulism Hypercalcemia Myopathies Periodic paralyses, Dermatomyositis Critical illness myopathy/polyneuropathy

Work up Serum creatine kinase (CK) may be mildly elevated or normal CSF studies are essential for diagnosis. protein is elevated to more than twice the upper limit of normal Glucose level is normal No pleocytosis. Fewer than 10 white blood cells/mm3 are found. Bacterial cultures are negative

Results of stool cultures are rarely positive Serologic testing for Campylobacter and Helicobacter infections helps establish the cause does not alter the course of treatment. Results of stool cultures are rarely positive The infection is self-limited (occurs for about 3 days), and the neuropathy follows the acute gastroenteritis.

MRI Of the spinal cord may be indicated to rule out disorders. MRI findings include thickening of the cauda equina and intrathecal nerve roots with gadolinium enhancement. These finds are fairly sensitive and are present in >90% of patients

NCS Motor NCVs are greatly reduced Sensory nerve conduction time is often slow. Electromyography (EMG) shows evidence of acute de-nervation of muscle.

Antiganglioside antibodies Mainly against GM1 and GD1 Sometimes elevated in the serum in Guillain-Barré syndrome, particularly in cases with primarily axonal rather than demyelinating neuropathy

biopsies Muscle and nerve is not usually required for the diagnosis

TREATMENT In early stages of this acute disease Should be admitted to the hospital for observation because the ascending paralysis can rapidly involve respiratory muscles during the next 24 hr Respiratory effort (negative inspiratory force, spirometry) must be monitored to prevent respiratory failure and respiratory arrest.

Rapidly progressive ascending paralysis slow progression observation for stabilization spontaneous remission without treatment possible Rapidly progressive ascending paralysis Intravenous immunoglobulin (IVIG), administered for 2, 3, or 5 days. A commonly recommended protocol is IVIG 0.4 g/kg/day for 5 consecutive days. Plasmapheresis and/or immunosuppressive drugs if IVIG is ineffective. Steroids are not effective.

Supportive care Respiratory support Prevention of decubiti in children with flaccid tetraplegia Treatment of secondary bacterial infections

PROGNOSIS Usually benign, and spontaneous recovery begins within 2-3 wk. Most patients regain full muscular strength some are left with residual weakness. The tendon reflexes are usually the last function to recover. Improvement usually follows a gradient opposite the direction of involvement: bulbar function recovering first lower extremity weakness resolving last. Bulbar and respiratory muscle involvement can lead to death if the syndrome is not recognized and treated.

3 clinical features are predictive of poor outcome with sequelae: Cranial nerve involvement Intubation Maximum disability at the time of presentation. The electrophysiologic features of conduction block are predictive of good outcome.

Easy fatigue is one of the most common chronic symptoms Among patients with the axonal form of Guillain-Barré syndrome, most who had slow recovery over the first 6 mo could eventually walk, although some required years to recover. EMG and NCV electrophysiologic studies do not necessarily predict the long-term outcome.

Chronic inflammatory demyelinating polyradiculoneuropathies (CIDP, sometimes called chronic inflammatory relapsing polyneuritis or chronic unremitting polyradiculoneuropathy) Chronic varieties of Guillain-Barré syndrome Recur intermittently Do not improve Progress slowly and relentlessly for periods of months to years. About 7% of children with Guillain-Barré syndrome suffer an acute relapse.