Myocerebellar Disorder

At a glance

It is a medical condition where patients show cerebellar ataxia accompanied by pancytopenia, hypoplastic anemia, acute myelomonocytic leukemia, or decreased bone marrow mitotic activity.

Synonym

Ataxia-Pancytopenia Syndrome.

Incidence

The exact incidence remains unknown. There are only few cases that have been described in the literature.

Genetic inheritance

It is believed inherited as an autosomal dominant pattern. The hematopoietic cytopenias that characterize the Ataxia-Pancytopenia Syndrome appear to be caused by the postulated role of SAMD9L in the regulation of cell proliferation.

Pathophysiology

Progressive expansion of clone of cells with monosomy 7 has been shown, but sensitivity to bleomycin suggests this may also be a chromosomal instability disorder.

Diagnosis

Red cell, platelet, and leukocytes abnormalities. There may be lymphomas or leukemias. Radiologic investigation shows cerebellar atrophy on CT scan. Laboratory investigations show monosomy 7 mosaicism, and electromyographic studies show reduced nerve conduction velocities.

Clinical aspects

Patients may show pancytopenia, hypoplastic anemia, acute myelomonocytic leukemia, or decreased bone marrow mitotic activity. On examination, cerebellar ataxia, brisk deep tendon reflexes, bilateral Babinski reflexes, diminished vibratory sensation in the legs, and unsteady gait can be found. Purpura may be present, and some cases show telangiectasia or angiokeratomata of the skin. Nystagmus and dysmetria are often present (cerebellar signs). Patients usually die of hypoplastic anemia or leukemia.

Precautions before anesthesia

Complete workup, including neurologic and motor milestones, family history, and previous problems. Blood tests are necessary because of marrow involvement, blood count, and clotting profile. Because of potential for defective immunity, the patient may have recurrent pulmonary, sinus, or urinary tract infections. Severe anemia may be present from an early age.

Anesthetic considerations

Check hemoglobin, hematocrit, and pulmonary function as indicated. Treat anemia if severe. Ensure sterile technique for venipuncture (reverse isolation).

Pharmacological implications

Antibiotics may be required.

References