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What is Hereditary
Spastic Paraplegia?Hereditary spastic paraplegia (HSP), also called familial spastic paraparesis (FSP), refers to a group of inherited disorders that are characterized by progressive weakness and stiffness of the legs. Though the primary feature of HSP is severe, progressive, lower extremity spasticity, in more complicated forms it can be accompanied by other neurological symptoms. These include optic neuropathy, retinopathy (diseases of the retina), dementia, ataxia (lack of muscle control), icthyosis (a skin disorder resulting in dry, rough, scaly skin), mental retardation, peripheral neuropathy, and deafness. Diagnosis is primarily by neurological examination and testing to exclude other disorders. Specialized genetic testing and diagnosis are available at some medical centers.
There are no specific treatments to prevent, slow, or reverse HSP. Symptomatic
treatments used for other forms of chronic paraplegia are sometimes helpful.
Regular physical therapy is important for improving muscle strength and preserving
range of motion.
The prognosis for individuals with HSP varies. Some cases are seriously disabling
while others are less disabling and are compatible with a productive and full
life. The majority of individuals with HSP have a normal life expectancy.
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Arnold-Chiari Malformation is a condition in which the cerebellum portion of
the brain protrudes into the spinal canal. It may or may not be apparent at birth.
Arnold-Chiari I type malformation usually causes symptoms in young adults and
is often associated with syringomyelia, in which a tubular cavity develops within
the spinal cord. Arnold-Chiari II type malformation is associated with myelomeningocele
(a defect of the spine) and hydrocephalus (increased cerebrospinal fluid and
pressure within the brain), which usually are apparent at birth. Myelomeningocele
usually causes paralysis of the legs and, less commonly, the arms. If left untreated,
hydrocephalus can cause mental impairment. Either type of Arnold-Chiari Malformation
can cause symptoms of headache, vomiting, difficulty swallowing, and hoarseness.
Adults and adolescents who are unaware they have Arnold-Chiari I type malformation
may develop headache that is predominantly located in the back of the head
and is increased by coughing or straining. Symptoms of progressive brain impairment
may include dizziness, an impaired ability to coordinate movement, double vision,
and involuntary, rapid, downward eye movements.
Infants and children with myelomeningocele may require surgery to repair protrusion
of the meningeal sac into the spinal cord. Hydrocephalus may be treated with
surgical implantation of a shunt to relieve increased pressure on the brain.
Some adults with Arnold-Chiari Malformation may benefit from surgery in which
the existing opening in the back of the skull is enlarged.
Infants with very severe malformations may have life-threatening complications.
Most patients who have surgery experience a reduction in their symptoms. Some
patients may experience prolonged periods of relative stability.
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Drug therapy including flunarizine may help to reduce the severity and duration
of attacks of paralysis associated with the more serious form of alternating
Children with the benign form of alternating hemiplegia have a good prognosis.
However, those who experience the more severe form have a poor prognosis because
intellectual and mental capacity do not respond to drug therapy, and balance
and gait problems continue. Over time, walking unassisted becomes difficult
Familial periodic paralyses are a group of inherited neurological disorders caused
by mutations in genes that regulate sodium and calcium channels in nerve cells.
They are characterized by episodes in which the affected muscles become slack,
weak, and unable to contract. Between attacks, the affected muscles usually work
The two most common types of periodic paralyses are:
Hypokalemic periodic paralysis is characterized by a fall in potassium
levels in the blood. In individuals with this mutation attacks often begin
in adolescence and are triggered by strenuous exercise or high carbohydrate
meals. Weakness may be mild and limited to certain muscle groups, or more severe
and affect the arms and legs. Attacks may last for a few hours or persist for
several days. Some patients may develop chronic muscle weakness later in life.
Hyperkalemic periodic paralysis is characterized by a rise in potassium
levels in the blood. Attacks often begin in infancy or early childhood and
are precipitated by rest after exercise or by fasting. Attacks are usually
shorter, more frequent, and less severe than the hypokalemic form. Muscle spasms
Treatment of the periodic paralyses focuses on preventing further attacks
and relieving acute symptoms. Avoiding carbohydrate-rich meals and strenuous
exercise, and taking acetazolamide daily may prevent hypokalemic attacks. Attacks
can be managed by drinking a potassium chloride oral solution. Eating carbohydrate-rich,
low-potassium foods, and avoiding strenuous exercise and fasting, can help
prevent hyperkalemic attacks
The prognosis for the familial periodic paralyses varies. Chronic attacks
may result in progressive weakness that persists between attacks. Some cases
respond well to treatment, which can prevent or reverse progressive muscle
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Locked-in syndrome is a rare neurological disorder characterized by complete
paralysis of voluntary muscles in all parts of the body except for those that
control eye movement. It may result from traumatic brain injury, diseases of
the circulatory system, diseases that destroy the myelin sheath surrounding nerve
cells, or medication overdose. Individuals with locked-in syndrome are conscious
and can think and reason, but are unable to speak or move. The disorder leaves
individuals completely mute and paralyzed. Communication may be possible with
blinking eye movements
There is no cure for locked-in syndrome, nor is there a standard course of
treatment. A therapy called functional neuromuscular stimulation, which uses
electrodes to stimulate muscle reflexes, may help activate some paralyzed muscles.
Several devices to help communication are available. Other treatment is symptomatic
The prognosis for those with locked-in syndrome is poor. The majority of individuals
do not regain function.
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