Adams and Victor's Principles of Neurology

 984
Part 4
MAJOR CATEGORIES OF NEUROLOGIC DISEASE
As already mentioned, Crowe and coworkers expressed
the view that 80 percent of patients with von Reckling-
hausen disease can be diagnosed by the presence of more
than 6 café-au-lait spots. Of the remaining 20 percent,
those older than 21 years of age will be found to have mul-
tiple cutaneous tumors, axillary freckling, and a few pig-
mented spots; in those younger than 21 years of age with
no dermal tumors and only a few café-au-lait patches, a
positive family history and radiographic demonstration of
bone cysts will be helpful in some instances. Café-au-lait
spots and cutaneous tumors should always be sought, for
they may help the neurologist diagnose an otherwise
obscure progressive spinal syndrome, a cerebellopontine
angle syndrome, bilateral deafness, progressive blindness,
and an occasional case of precocious puberty, hydroceph-
alus, or mental retardation.
Because of the many potentially dangerous conditions
that accompany classic NF, the initial clinical evaluation
should be supplemented by a number of ancillary exami-
nations that may include measurement of IQ, EEG, slit-
lamp examination of irides, visual and auditory evoked
responses, and CT scans or MRI of cranium and, some-
times, of the spine and mediastinum. In the series
reported by Duffner and colleagues, 74 percent of cases
had abnormal signals in T2-weighted images of the basal
ganglia, thalamus, hypothalamus, brainstem, and cerebel-
lum. The EEG was abnormal in 25 percent. If there is sus-
picion of a pheochromocytoma, 24-h urine should be
tested for metabolites of epinephrine. Each of these tests
not only is an aid to diagnosis but also is essential to the
effective management of the illness.
Treatment
The skin tumors should not be excised unless they are
cosmetically objectionable or show an increase in size,
suggesting malignant change. The effects of radiother-
apy on these lesions are so insignificant that they do not
justify the risk of exposure. Plexiform neuromas about
the face pose especially difficult problems. Here one
must resort to plastic surgery, but the results are not
always satisfactory because the growths may encompass
distal branches of cranial nerves (with risk of greater
paralysis after surgical excision) or alter the underlying
bone, the latter being either eroded from pressure or
hypertrophied from increased blood supply. Cranial and
spinal neurofibromas are amenable to excision, and the
gliomas and meningiomas usually demand surgical mea-
sures as well. Here the differentiation of hamartomas
from gliomas of structures such as the optic nerves,
hypothalamus, or pons may be difficult. Bilateral optic
nerve gliomas are usually treated with radiation; unilat-
eral ones are excised. Peripheral nerve tumors that have
undergone malignant (sarcomatous) degeneration pose
special surgical problems.
Affected individuals should be advised not to have chil-
dren, a precaution that may not be necessary because fer-
tility, especially in males, seems to be reduced by the
disease. Prognosis varies with the grade of severity, being
most favorable in those with only a few lesions. But the
disease is always progressive, and the patient should
remain under surveillance.