In Handbook of Clinical Neurology

Brucellosis remains an important health problem in some parts of the world. The disease has virtually disappeared in Western countries but is still endemic in others. In Kuwait, with a population of 1.6 million, a total number of 1168 fresh cases of brucellosis were reported in 1985, an incidence of 68.9/100,000 population. The general presentation of brucellosis remains well recognized and is mainly that of generalized weakness associated with fever in addition to the various manifestations of the disease which may involve the joints as well as other organs. Excluding the common neuropsychiatric symptoms of malaise and generalized ill-health, which are commonly associated with systemic brucellosis, actual central nervous system (CNS) involvement is not very common. The incidence has been reported to be between 3 and 25% of cases of generalized brucellosis but the total number of reported cases with CNS involvement is small. Nine cases were reported in 1963 (Finchman et al.). Four further series have reported a total of 32 cases (Jogtekar & Nagalotimath, 1976; Abramsky, 1977; Larbrisseau et al., 1978; Bashir et al; 1985), the largest of which reported on eleven patients (Larbrisseau et al., 1978). A recent report of 19 patients, the largest number of cases from a single institution, indicates an incidence of neurobrucellosis somewhere between 3 and 5% of cases of generalized brucellosis (Shakir et al., in press). In endemic areas the mode of infection is usually through ingesting raw milk or cheese. The animals implicated are goats or cattle and, in our particular community, camels. The presentation of neurobrucellosis is diverse. The commonest is that of an acute process with headache, vomiting, clouding of consciousness progressing to loss of consciousness with or without epileptic seizures. Papilloedema has been reported and the computed tomographic (CT) scan in those cases is usually normal but may show features of cerebral oedema. Examination of the cerebro-spinal fluid (CSF) reveals a lymphocytic type of reaction with a raised protein. The blood sugar may be low (below 2 mmol/1) in one-third of the cases. The organism can be cultured from the CSF in a minority of cases only. The pathology of the disease is assumed to be a direct effect of the organism or its toxin on the meninges and the brain. The diagnosis in endemic areas can be difficult in the acute stage, as a large number of the population have a positive agglutination titre. The blood and CSF enzyme linked immunosorbant assay (ELISA) has been reported to be specific (Sippel et al., 1982; Araj et al., 1986). The presentation on the other hand can be completely different, with a much more chronic process involving the peripheral and/or the central part of the nervous system. The exact nature of the pathology here is not well understood. There are indeed very few reports on actual pathology, but epidural granulomata have been reported (Larbrisseau et al., 1978). In addition, spinal roots, both motor and sensory, showed demyelination. Ascending and descending tract degeneration of spinal cord has also been reported on autopsy (Finchman et al., 1963). The peripheral form is that of a slowly progressive flaccid paraparesis associated with backache. The weakness is ofa lower motor neurone type and usually involves the legs only. The process may take several months in evolution and the involvement clinically is that of a proximal polyradiculoneuropathy with areflexia and minimal superficial sensory involvement. Electromyography shows a predominantly proximal polyradiculoneuropathy with features of denervation, moderate slowing of nerve conduction velocity and delayed F wave latency and absent H reflex. The sural nerve potential is absent in some cases. Occasionally features of axonal involvement are noted in addition. The upper limbs are rarely affected. Examination of the CSF shows a raised protein, lymphocytic pleocytosis and reduced sugar content in some cases. High IgG content and oligoclonal bands have also been reported (Silva et al., 1980). The organism can rarely be grown from such cases although on occasions it has been cultured from the CSF (Sahs, 1978). Although myelography in such cases is usually normal, arachnoiditis has been reported (Shakir et al., in press). The diagnosis is confirmed in the suspected