Subclinical cranial nerve involvement in hereditary motor and sensory neuropathy: a combined conduction study with electrical and magnetic stimulation.
OBJECTIVE
To evaluate the electrophysiological findings of clinically unaffected cranial nerves (facial, accessory and hypoglossal nerves) in hereditary motor and sensory neuropathy (HMSN).


METHODS
The conduction times of the facial, accessory, and hypoglossal nerves in 10 patients with HMSN type I (HMSN I), 2 patients with HMSN Type II (HMSN II), and 20 normal controls were determined. The extra- and intracranial segments of the cranial nerves were stimulated electrically and magnetically, respectively. The relationships between the conduction parameters of the cranial nerves and limb nerves were analyzed.


RESULTS
In patients with HMSN I, the conduction times of the distal and proximal segments were significantly prolonged in all 3 cranial nerves. A positive correlation was found between the conduction parameters of the cranial nerves and the limb nerves.


CONCLUSIONS
Electrophysiological involvement of the whole segment of the facial, accessory and hypoglossal nerves is common in patients with HMSN I without clinical signs of alterations. The degree of conduction slowing of the facial, accessory, and hypoglossal nerves paralleled that of limb nerves.
Kumagai-Eto
Rumi
R
Third Department of Internal Medicine, Hiroshima University School of Medicine, 1-2-3 Kasumi, Minami-Ku, Hiroshima, Japan.
Kaseda
Yumiko
Y
Tobimatsu
Shozo
S
Uozumi
Takenori
T
Tsuji
Sadatoshi
S
Nakamura
Shigenobu
S
D000055:Accessory Nerve / Q000503:physiopathology*; D000200:Action Potentials; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002607:Charcot-Marie-Tooth Disease / Q000503:physiopathology*; D004558:Electric Stimulation; D005121:Extremities / Q000294:innervation; D005154:Facial Nerve / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007002:Hypoglossal Nerve / Q000503:physiopathology*; D008280:Magnetics; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction; D010525:Peripheral Nerves / Q000503:physiopathology; D013997:Time Factors