| |
|
|
GUILLAIN-BARRÉ SYNDROME |
|
|
|
The Guillain-Barré syndrome is an immune-mediated, rapidly progressive, predominantly
motor polyneuropathy that often leads to paralysis, along with bulbar and
respiratory compromise. It is one of the most common of all
neuromuscular
emergencies.
The first description of "ascending
paralysis" was made by a French physician
Jean Landry in 1859. Landry's description was based on ten cases,
five of his own and five from the medical literature.
The description in Landry's original paper is as germane today as it was
then:
"The sensory and motor systems
may be equally affected. However the main problem is usually a motor disorder
characterised by a gradual diminution of muscular strength with flaccid limbs
and without contractures, convulsions or reflex movements of any kind. In almost
all cases micturition and defaecation remain normal. One does not observe any
symptoms referable to the central nervous system, spinal pain or tenderness,
headache or delirium. The intellectual faculties are preserved until the end.
The onset of the paralysis can be preceded by a general feeling of weakness,
pins and needles and even slight cramps. Alternatively the illness may begin
suddenly and end unexpectedly. In both cases the weakness spreads rapidly from
the lower to the upper parts of the body with a universal tendency to become
generalised.
The first symptoms always
affect the extremities of the limbs and the lower limbs particularly. When the
whole body becomes affected the order of progression is more or less constant:
(1) toe and foot muscles, then the hamstrings and glutei, and finally the
anterior and adductor muscles of the thigh; (2) finger and hand, arm and then
shoulder muscles; (3) trunk muscles; (4) respiratory muscles, tongue, pharynx,
oesophagus, etc. The paralysis then becomes generalised but more severe in the
distal parts of the extremities. The progression can be more or less rapid. It
was eight days in one and fifteen days in another case which I believe can be
classified as acute. More often it is scarcely two or three days and sometimes
only a few hours.
When the paralysis reaches its
maximum intensity the danger of asphyxia is always imminent. However in eight
out of ten cases death was avoided either by skillful professional intervention
or a spontaneous remission of this phase of the illness. In two cases death
occurred at this stage . . . When the paralysis recedes it demonstrates the
reverse of the phenomenon which signaled its development. The upper parts of the
body, the last to be affected, are the first to recover their mobility which
then returns from above downwards." |
|
|
|
Later, French physicians, Georges Charles Guillain,
Jean-Alexandre Barré and
André Strohl published their classic paper in
1916 on the Syndrome of Radiculoneuritis. They were the first to note the
combination of absent reflexes and an elevated protein level in the
cerebrospinal fluid that was not accompanied with a high white blood cell count.
This was a key point, as syphilis and tuberculosis, both common at the time,
were associated with a CSF pleocytosis. In 1927, the term Guillain-Barré
syndrome was first used at a scientific presentation (Strohl's name was omitted
not only from the title of the presentation but also from the list of authors in
the reference to the 1916 paper; possibly because Strohl was not a professor of
neurology).
Over the years, the syndrome has been known as Guillain-Barré syndrome,
Guillain-Barré-Strohl syndrome and Laundry-Guillain-Barré-Strohl syndrome, among
other names. |
|
|
|
Above: Electronmicrograph of a normal myelinated axon (left) and
an axon from a patient with GBS (right). Note the destruction and disarray of
the surrounding myelin sheath in the GBS patient. |
|
In the modern day, Guillain-Barré is most properly considered a syndrome that
has several variations.
The most common is acute inflammatory demyelinating
polyneuropathy (AIDP) where the immune attack is presumably directed against
peripheral nerve myelin (see figure above). Other variants are directed purely
against the motor axon (acute motor axonal neuropathy), the motor and sensory
axons (acute motor-sensory axonal neuropathy) or certain subset of nerves (e.g.,
Miller Fisher variant of ophthalmoplegia, ataxia and areflexia).
Although the overall prognosis is favorable for more
than 80% of patients, the hospital course is frequently long, followed by a
prolonged recuperation.
People of all ages can be affected, although AIDP is most common in young
adults. An antecedent event is found in approximately 60% of patients; it is
often an upper respiratory infection or gastroenteritis. Campylobacter,
cytomegalovirus, Epstein-Barr virus, HIV, vaccination, surgery, trauma, and
malignancy (especially lymphoma) have also been associated with AIDP.
|
|
Common Clinical Signs and Symptoms
• Ascending paralysis (weakness beginning distally and moving proximally)
• Paresthesias in the fingers and toes at the same time,
often with little objective
sensory loss
• Gait disturbance
(indeed, it is not unusual for a patient to be sent home from the emergency
department with very mild gait ataxia as the only sign, only to return the next
day with rapidly progressing weakness)
• Rapid
progression over hours or days
• Often
involves facial and bulbar muscles
• Respiratory insufficiency results in intubation
and mechanical ventilation in one-third of patients
• Loss of
reflexes (areflexia is common even early on)
•
Pain - either deep aching in muscles, or dysesthetic pain in the extremities, or
pain involving the entire spine (note: Laundry's description specifically states
that pain was not present; however, when larger numbers of patients are studied,
approximately 1/3 of patients have prominent pain).
• Autonomic Instability (e.g., tachycardia, some bladder and bowel dysfunction,
hypotension, cardiac dysrhythmias)
|
|
Diagnostic Evaluation
There are few neuromuscular disorders that present in such an acute and dramatic
manner. The differential diagnosis includes botulism, myasthenic crisis,
poliomyelitis and a few rare neuropathies (i.e., porphyria, arsenic, and tick
paralysis). An acute myelopathy can also mimic GBS. Due to spinal shock,
reflexes may be absent initially. The presence of a sensory level and prominent
bladder dysfunction are usually the important signs pointing to the diagnosis of
an acute myelopathy.
Two laboratory tests are often helpful in supporting the diagnosis:
•
CSF analysis (typical finding is an elevated protein (100-1000mg/dL) with no pleocytosis)
•
Electromyography and Nerve Conduction Studies
(typical findings are an acquired, acute demyelinating neuropathy - slowed
velocities, conduction block and prolonged F and H responses)
|
|
|
|
Above: Median nerve conduction study in a
patient with GBS. The top trace shows the response stimulating at the wrist, and
the bottom trace stimulating at the antecubital fossa. In normals, the amplitude
of both are very similar. In GBS, there is often "conduction block" due to
demyelination. In this case, there is a conduction block pattern between the
wrist and antecubital fossa sites. Conduction block is only seen with acquired
(not inherited) demyelinating peripheral neuropathies. |
Treatment
• Observation / management in an ICU with frequent respiratory monitoring
• Intubation
and mechanical ventilation for bulbar or respiratory compromise
• Avoidance
and treatment of medical complications (i.e., GBS patients are at risk for deep
venous thrombosis, pulmonary embolism,
pneumonia, urinary tract infection, etc.)
•
Immune Treatment
High dose intravenous gammaglobulin (IVIG) (5 daily infusions of 400
mg/kg/dose)
OR
Plasmapheresis (one exchange daily for 4-5 days)
• Physical Therapy
(range of motion exercises to prevent contractures)
|
|
|
|
