Peripheral neuropathy associated with mitochondrial disorders: 8 cases and review of the literature.
Forty-three cases of peripheral neuropathy (PN) have been reported in the literature with a proven mitochondria (mt) DNA mutation, and 21 had a peripheral nerve biopsy (PNB). We studied 8 patients, 1 of whom had severe sensory PN, 3 mild PN, and 4 subclinical PN. Nerve biopsy was performed in every case; all patients showed axonal degeneration and 4 showed features of primary myelin damage. In addition, there were 2 crystalline-like inclusions in the Schwann cell cytoplasm of a patient with MERRF, and 1 in a patient with multiple deletions on the mtDNA. There are 11 cases of PNB in the literature with axonal lesions, 5 with demyelination, and 4 with mixed lesions. One PNB was not modified. A few crystalline-like inclusions were seen in 1 case of MERRF. Such inclusions were first reported in the Schwann cell cytoplasm of unmyelinated fibers in a patient with Refsum disease and were considered to be modified mitochondria. However, their mitochondrial origin remains debatable.
Bouillot
S
S
Neuropathology, Victor Segalen University, Bordeaux, France.
Martin-Négrier
M L
ML
Vital
A
A
Ferrer
X
X
Lagueny
A
A
Vincent
D
D
Coquet
M
M
Orgogozo
J M
JM
Bloch
B
B
Vita
C
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D028361:Mitochondrial Diseases / Q000150:complications / Q000235:genetics* / Q000473:pathology*; D009154:Mutation / Q000235:genetics; D009413:Nerve Fibers, Myelinated / Q000473:pathology; D010523:Peripheral Nervous System Diseases / Q000150:complications / Q000235:genetics* / Q000473:pathology*