Neurological Disorders: Refsum Disease

Refsum Disease, very rare in incidence is a genetically mediated neurological disorder with certain characteristic skin manifestations too so this disease is more appropriately called as a neurocutaneous syndrome.

A dietary substance by name phytanic acid cannot be properly metabolized in this disease and this substance accumulates and acts as a toxin and irritates and/or damages structures related with nervous system, skin, bones etc.

It is considered as a peroxisomal disorder. One of the peroxisomal enzymes by name phytanol-coenzymeA hydroxylase which metabolizes phytanic acid is deficient in these patients.

It is an autosomal recessive type disorder and few different gene mutations leads into the same type of disease (genetically heterogeneous).

There are adult and infantile types. The adult type may be classified further as type 1 & 2.

• Manifestations are slowly progressive with intermittent exacerbations
• Cerebellar – gat ataxia, in coordination
• Peripheral neuropathy – foot drop, weakness, sensory manifestations of the limbs, decreased or absent tendon reflexes
• Retnitis pigmentosa – gradual reduction in vision beginning with night vision
• Loss of smell abilities
• Hearing difficulties due to 8th cranial nerve involvement
• Skin changes- icthyosis
• Bone abnormalities etc.

The following investigations are usually employed while arriving at the diagnosis of this condition;

• Abnormally elevated blood levels of phytanic acid
• A decrease in high & low density cholesterols in the blood
• CSF (cerebrospinal fluid) showing raised csf protein levels (albumin)
• Abnormal MRI of the brain
• EMG/NCS (electromyography & nerve conduction study) to show neuropathic findings

There is no curative treatment yet available for this condition. Treatment is symptomatic & supportive and includes;

• Dietary elimination of chlorophyl (source of phytanic acid)
• Plasmapheresis during acute exacerbations
• Skin care
• Skeletal (bone) care etc.

A neurologist is commonly involved in the management of this condition.