Metachromatic Leukodystrophy

Diagnosis

During the physical exam, the physician may observe signs that indicate metachromatic leukodystrophy (MLD), such as abnormal gait, increased muscle tone and stiffness, abnormal deep tendon reflexes, abnormal eye movements and other signs of vision problems.

The patient may have the following tests to diagnose MLD or determine the extent and severity of the impact MLD has had on brain and body functions.

Blood and Urine Tests

Blood samples are used to test for an enzyme deficiency in the white blood cells that causes MLD. Urine tests check for an accumulation of sulfatides.

The patient's biological parents may also have blood and urine samples to confirm that they carry the defective gene that causes MLD.

Nerve Conduction Study (Electroneurograph)

This test measures electrical nerve impulses. Two electrodes are taped to the patient's skin in the affected area of the body. A small shock is passed through to measure the electrical impulses from one electrode to the other. This test is used to look for peripheral neuropathy (nerve damage), a common finding in patients with MLD.

Magnetic Resonance Imaging (MRI)

This test uses powerful magnets and radio waves to produce a detailed, three-dimensional view of the brain. Patients may have a brain MRI to determine if characteristics of MLD are present, including abnormal white matter (leukodystrophy) and atrophy, (shrinking) of the brain.

Psychological and Cognitive Tests

For patients who may have late juvenile or adult forms of MLD, the physician may order tests of the patient's psychological and cognitive (thinking) abilities. These tests may help in determining the extent and severity of MLD on the patient's brain functions.