Cranial neuropathy in neurosarcoidosis. (Imaging Clinic).

Sarcoidosis is a multisystem granulomatous disease. Its neurologic manifestations usually occur as a part of the spectrum of the systemic disorder. Cranial neuropathy is a common manifestation of neurosarcoidosis, occurring in as many as 75% of patients. (1,2) Most patients have more than one cranial neuropathy. The cranial nerve most often involved is the facial nerve. The VIIIth cranial nerve is involved in 10 to 20% of cases. (2'3 )

The case presented here is that of a 44-year-old black man with mild bilateral sensorineural hearing loss who had been monitored for several years. Coronal-section (figure 1) and axial-section (figure 2) magnetic resonance imaging (MM) examinations of the brain had revealed symmetrical enhancing lesions that involved the internal acoustic canals and the trigeminal nerves. These findings suggested the presence of schwannomas and led to a presumptive diagnosis of neurofibromatosis type II. The patient also developed progressively worsening low back pain and experienced difficulty walking secondary to myelopathy and peripheral neuropathy. Further evaluation of the spine by MRI revealed the presence of a space-occupying lesion at the level of the conus medullaris and involvement of the leptomeninges in the thoracic and cervical areas. Biopsy analysis identified a granulomatous process that was consistent with sarcoidosis involving the distal spinal cord and leptomeninges.

Following surgical treatment of the spine, the patient recovered almost completely. Further treatment with corticosteroids was prescribed. On follow-up MRI examinations, a decrease in the enhancement of the cranial nerve lesions was observed. However, the patient experienced no significant alleviation of his sensorineural hearing loss.

References

(1.) Gullapalli D, Phillips LH II. Neurologic manifestations of sarcoidosis. Neurol Clin 2002;20:59-83.

(2.) Delaney P. Neurologic manifestations in sarcoidosis. Review of the literature, with a report of 23 cases. Ann Intern Med 1977;87:336-45.

(3.) Zouaoui A, Maillard JC, Dormont D, et al. [MRI in neurosarcoidosis]. J Neuroradiol 1992;19:271-84.

From the Department of Radiology (Dr. Palacios) and the Department of Otorhinolaryngology (Dr. Rigby and Dr. Smith), Lousiana State University Health Sciences Center, New Orleans.