peripheral neuropathy

Psychomotor development is initially normal but signs of delay are usually present during the first year of life.  Patients may be able to walk but only with support.  Pyramidal and cerebellar dysfunction, muscle weakness and wasting, dysarthria, truncal hypotonia, intention tremor, and spasticity are evident during the first decade.  Some have seizures.  Cognitive impairment ranges from mild to moderate.  Most patients become wheelchair-bound late in the first decade of life and some do not survive beyond childhood.

Hypomyelination and mild axonal loss may be seen in peripheral nerve biopsies while neuroimaging shows evidence of diffuse and progressive cerebral white matter atrophy.

This is a disorder of copper metabolism.  It is associated with severe liver disease, often beginning with signs of recurrent jaundice, sometimes a hepatitis-like illness, and often culminating in liver failure.  Hepatobiliary malignancies are a significant risk, occurring in more than 1 percent of patients.  Neurologic toxicity leads to various movement disorders such as tremors, poor coordination, dystonia, and choreoathetosis.  Many patients have mental symptoms such as depression, neurotic behavior, and personality disturbances.  Some have a mask-like facies and pseudobulbar symptoms.  Symptoms can appear anytime from 3 years of age to over 50.  Other organs such as kidney, pancreas, heart and even joints may also be involved.

Patients often have a low serum ceruloplasmin, low copper levels, increased urinary excretion of copper, and increased concentration of copper in the liver.

There is considerable variation in the time of onset and rate of progression in Krabbe disease, even within families.  Patients with infantile disease may present with symptoms at about 6 months of life, while others are not diagnosed until late childhood or adolescence.  Some evidence of psychomotor retardation is often the first sign of disease with ataxia and limb spasticity soon following.  Irritability is an early sign.  Neurophysiologic studies often show abnormal nerve conduction and this has been documented even in newborns.  The disorder is one of progressive neurodegeneration of both central and peripheral nervous systems leading to weakness, seizures and loss of protective reflexes.  The MRI may reveal T2 hyperintensity in cerebral and cerebellar white matter, internal capsules and pyramidal tracts.  Infection and respiratory failure are responsible for most deaths.

The life-span of Infants with Krabbe disease is approximately one year while those with late-onset disease may not develop symptoms until almost any age and the clinical course is highly variable.

This is a form of albinism with other systemic features such as adenopathy, hepatosplenomegaly, neutropenia, and susceptibility to infection (especially gram positive organisms).  The hypopigmentation is evident at birth but may be patchy.  The hair has been described as having a blue-green metallic sheen.  It may also be sparse.  Patients have an increased risk of leukemia and lymphoma-like disease.  Peripheral sensory-motor neuropathy and ataxia are common in older individuals.  Thrombocytopenia can lead to easy bruising and extensive bleeding.  Neutrophils are often few in number and deficient in chemotactic and bacterial activity.  Pyoderma and peridontitis can be severe.  Survival without treatment is between 3 and 4 years but those who survive eventually develop lymphohistiocytic infiltration of major organs, bone marrow and peripheral nerves as young adults.

Giant peroxidase-positive inclusions in white blood cells are diagnostic.

This is a sensorineural disease of myelination that causes a polyneuropathy with muscular weakness and sensory deficits.  CMT4B2 is characterized by abnormal myelin sheath folding.  Symptoms of lower limb weakness and evidence of muscle atrophy commonly appear in the middle of the first decade with progression to upper limb involvement.  Areflexia follows with development of pes cavus and hammertoes.  Motor nerve conduction velocities may be severely reduced and muscle biopsies show severe loss of myelinated fibers and focal myelin sheath folding.

The relatively common occurrence and the protean nature of Fabry disease has lead to its designation by some as the Great Imposter, replacing syphilis to which this term was previously applied.  Compounding the diagnostic difficulties in some individuals is the absence of the complete classical phenotype due to the presence of DNA variants that may modify the expression of some the clinical features.

Most signs present in the first or second decade of life with generally earlier onset in males.  The presence of proteinuria before the age of 20 years in the absence of other primary kidney disease should always raise the possibility of Fabry disease.  However, the diagnosis is often not made until the third decade in males and the fourth decade in females.  Glycosphingolipid inclusion deposits in endothelial cells are responsible for the systemic signs and symptoms including renal and heart disease which are the most common causes of premature death.  Small vessel involvement resulting in cerebrovascular disease and painful peripheral neuropathy can be debilitating. The risk of ischemic strokes is increased.  Cardiac manifestations include hypertrophic cardiomyopathy (60%), mainly involving the left ventricle, and dysfunction of the mitral and aortic valves (10 to 25%).  Dysfunction of renal glomeruli may progress to renal failure by the third to fifth decade in males.  The angiokeratomas and angiomas (most pronounced in a swimming trunk pattern) are secondary to vascular involvement of cutaneous vessels but are non-specific since they also occur in other lysosomal diseases.  The life expectancy of females is reduced by about 5 years and for males about 16 years compared with the general US population.

Involvment of the autonomic system manifests as intermittent fever, hypohidrosis, and poor temperature control.  Some patients have periodic crises of severe pain in the extremities as well as intermittent epigastric pain. Hearing loss and episodic tinnitus are common complaints.

Patients with Tangier disease have significant enlargement of the liver, spleen and lymph nodes.  The tonsils are also frequently enlarged and have a characteristic yellow-orange  coloration.  The enlargement of these organs is due to lipid infiltration.  Plasma levels of cholesterol and HDL are characteristically slightly low while triglycerides are mildly elevated.  Peripheral neuropathy and muscle atrophy can be debilitating.  Severe coronary artery disease is common with onset sometime in the 5^th decade.