Multiple cranial nerve involvement caused by Brucella melitensis.

A case of neurobrucellosis complicated by optic, abducens and vestibulocochlear nerve palsies is reported. Brucella melitensis was isolated in the cerebrospinal fluid, and the patient was diagnosed with retrobulbar neuritis. Despite medical treatment, the patient developed optic atrophy. Multiple cranial nerve involvement should be kept in mind in patients presenting with blurred vision and double vision, especially in regions where brucellosis is endemic.

Isolated monolateral neurosensory hearing loss as a rare sign of neuroborreliosis.

Lyme disease, or borreliosis, is a zoonosis transmitted by Borrelia burgdorferi which also involves the central nervous system (CNS), in 15% of affected individuals, with the occurrence of aseptic meningitis, fluctuating meningoencephalitis, or neuropathy of cranial and peripheral nerves. Encephalopathy with white matter lesions revealed by magnetic resonance imaging (MRI) scans in late, persistent stages of Lyme disease has been described. In this report, we describe a patient with few clinical manifestations involving exclusively the eighth cranial nerve, monolaterally and diffuse bilateral alterations of the white matter, particularly in the subcortical periventricular regions at cerebral MRI. This single patient study shows that the search for antibodies against Borrelia burgdoferi should always be performed when we face a leukoencephalopathy of unknown origin. An isolated lesion of the eighth cranial nerve can be the only neurologic sign in patients with leukoencephalopathy complicating Lyme disease.

Pontine cryptococcoma in a nonimmunocompromised individual: MRI characteristics.

The case of a pontine cryptococcoma in a nonimmunocompromised, previously healthy 16-year-old boy is presented. The patient had slowly progressive brainstem signs with right cranial nerves V, VII, and VIII palsies, and contralateral corticospinal and spinothalamic deficits. Magnetic resonance images (MRI) revealed, within the right pons, a 1-cm diameter round mass lesion, hypointense on T1-weighted images, hyperintense on T2-weighted images, and with rim enhancement after infusion of gadopentetate dimeglumine. This is the only report of the MRI findings in an isolated pontine cryptococcoma in an immunocompetent patient. Early recognition of this specific MRI pattern is essential, because complete recovery can be achieved with prompt antifungal treatment.

Latent herpes simplex virus type 1 in human vestibular ganglia.

Viral infection has been considered to be a possible pathogenesis of vestibular neuronitis, and reactivation of the herpes simplex virus (HSV) is one of the most likely causes. However, it remains unknown whether the human vestibular ganglia contain latent HSV. We examined 26 vestibular ganglia from autopsied adults in search of HSV type 1 (HSV-1). To detect HSV-1, we used polymerase chain reaction (PCR), in situ hybridization and immunohistochemical staining. HSV DNA was detected in 6 of 10 vestibular ganglia using the PCR method. However, the latency-associated transcript (LAT) of HSV-1 was negative in all of the 16 vestibular ganglia examined. No HSV antigen was detected in any of the ganglia. These results indicate that HSV-1 is latently infected in the human vestibular ganglia, and that LAT is transcribed weakly or not at all.

Experimental reactivation of HSV-I in rat vestibular ganglia.

Rats with no clinical symptoms after inoculation were administered with cyclophosphamide in order to reactivate HSV-I in the vestibular ganglia. After this immunosuppression, the vestibular ganglia, trigeminal ganglia, cerebrum, cerebellum and brainstem were examined immunohistologically in order to detect HSV-I. HSV-I antigen could not be detected by using indirect immunofluorescence or the ABC method, however, it could be detected by using the PCR method. In this study, latent infection of HSV-I was shown but reactivation could not be established. We need further investigations to determine the reactivation of HSV-I in the vestibular ganglia, to obtain an animal model of vestibular neuronitis.

Latent HSV-I infection in rat vestibular ganglia.

The vestibular ganglia of rats having no clinical symptoms after inoculation of HSV-I were examined by Polymerase Chain Reaction (PCR) in order to prove latent HSV-I infection. The rats were divided into two groups: one inoculated with HSV-I into the middle ear cavity (m.i. group), and the other into the peritoneal space (i.p. group). In the m.i. group, 67% of the vestibular ganglia on the inoculated side and 0% on the opposite side were positive. In the i.p. group, 60% of the vestibular ganglia on both sides were positive. These data indicate that HSV-I can establish latent infection in the vestibular ganglia. Furthermore, we assumed that reactivation of HSV-I genomes in the vestibular ganglia might lead to disorders of the vestibular system.

[Possible viral etiology of inner ear diseases (author's transl)]. / Mögliche virale Genese von Innenohrerkrankungen.

After a short review of the possible viral etiology of inner ear diseases viral titers of 20 patients with inner ear problems are given. In the history of nearly all patients a viral infection was found. Inspite of some positive results in the titrations no significance was seen. Therefore we refute a relation between viral infection and inner ear troubles; for a practical point of view virological diagnostics is not indicated.