Discussion:
In this study, a TBM patient with NCSE is reported. The frequency of
status epilepticus in TB patients is 7.6%.(9) Â However, to the best of
our knowledge, only 4 cases of TBM presenting with NCSE have been
reported in the literature (11-14). Seizures are reported in 50-73% of
children, and 10-38% of adults in the clinical course of TBM (15-17).
Both febrile and afebrile seizures can be the presenting feature of TBM
in children. The frequency of status epilepticus in TBM patients is
7.6%. It is reported that Convulsions are a significant predictor of
mortality (18). Our patient presented with altered level of
consciousness and unresponsiveness and persistent seizure activity on
the EEG that comprised 1 to 2-Hz continuous sharp and slow wave
activity. Inconsistent with our study, a study by Arman study et al.
(11) has reported a patient with NCSE due to tuberculosis meningitis who
had right frontal 1.5- to 2-Hz continuous focal sharp and slow waves. In
contrast in Oka study et al. (13), EEG showed left frontal 2.5- to 3-Hz
repetitive focal sharp wave activity compatible with NCSE.
Continuous epileptiform EEG activity in NCSE is expected to be higher
than 2.5 Hz, whereby when epileptiform discharges are less than 2.5Hz,
one out of three other criteria is needed to confirm the diagnosis of
NCSE including presence of mini-convulsive signs, evolution in amplitude
or frequency of discharges and responsiveness to intravenous
administration of benzodiazepines (19). Our patient had no
mini-convulsive signs but she had an obvious response to intravenous
diazepam and levetiracetam, both clinically and electrically. The
patient in Arman study et al. (11) responded to diazepam and phenytoin,
followed by midazolam infusion. In Oka study et al. (13) after
anticonvulsant treatment with levetiracetam, persistent EEG activity
ceased with the recovery of consciousness
In our study, recovery of consciousness and normalization of subsequent
EEGs with antiepileptic therapy have happened. A study by Kalita et al.
(19) on the 32 patients with highly probable tuberculous meningitis have
done. Evidence of extra-CNS tuberculosis were present in 6 patients; all
had pulmonary tuberculosis. The main abnormality in their EEG was
diffuse slowing of the background activity (69%).
Our patient had diffused sharp and wave activity with slow background
which is compatible with status epilepticus (20). Several reports
establish that 84% of CNS tuberculoma clearly showed low signal on T2-
weight images and 16% had lesions with central high signal thought to
represent caseating necrosis or tuberculous abscesses (21-23).
At an early stage of tuberculoma formation, the mass is isointense on
T1- and T2-weighted images and shows some contrast enhancement, that is
secondary to occurrence of inflammatory reactions and excess of giant
cells in the mass and a poor collagen capsule, that it becomes rich in
collagen, later in the course of disease. They give low signal on
T2-weighted images because of fibrosis, scar tissue (24). Rarely,
tuberculomas show calcification on CT, but it can appear as low signal
on MRI. All tuberculomas show ring or nodular contrast enhancement.
Almost one third of tuberculomas are multiple (25). Various differential
diagnosis should be considered in a patient presented with altered level
of consciousness and multiple ring-enhancing lesions, especially
neoplasms either metastasis or primary lymphoma and other infectious
diseases like fungus or bacterial endocarditis. Moreover, Tuberculomas
have a variety of different features that can mimic other
space-occupying lesions, such as neoplasms.
Metastases, multiple gliomata or meningiomas excluded by further
evaluations. No space occupying lesion was found in the chest and
abdominopelvic CT-scan. The pathology of her surgery was in favor of
diffuse granulomatous involvement.
The normal CSF glucose and protein levels are unusual but not
incompatible with the diagnosis of TB (26). Acid-fast bacilli are seen
in only 40% cases on initial CSF examination (27). The tuberculin test
is negative in 50% cases at presentation (28). Similar to Arman study
et al. (11) in this study, PCR of CSF was negative, but nested PCR assay
was positive. Nested PCR is a technique that reduces nonspecific
amplification of the DNA template. It increases the sensitivity and
specificity of the reaction and is useful on suboptimal nucleic acid
samples (29).
The presence of a low signal lesion on T2-weighted images that shows
ring or nodular contrast enhancement in a patient who has tuberculosis
elsewhere in the body and from a region in which tuberculosis is endemic
should suggest CNS tuberculoma.
The patient’s clinical findings, unexplained acute change of
consciousness, together with chest involvement, diffuse granulomatous
infiltration in uterus and ovaries, and multiple ring enhancement
lesions in brain MRI, led to the diagnosis of TBM. The positive response
of the patient to antituberculosis treatment also supported the
diagnosis.