Limbic encephalitis: Experience of a moroccan center

Seizures and epilepsy associated with central nervous system tuberculosis

Central nervous system (CNS) tuberculosis is a life-threatening condition that usually presents with seizures, particularly in children and HIV-infected patients. Tuberculous meningitis (TBM) and tuberculomas are the two forms of CNS tuberculosis that can present with seizures. Seizures usually resolve after successful treatment of the underlying infection. However, the success of the treatment is usually based on an early diagnosis. Delay in the treatment of CNS tuberculosis increases the risk of its associated complications, such as stroke. This would lead to the development of epilepsy. Early seizures may be related to meningeal irritation and cerebral edema, whereas late seizures are often associated with structural brain lesions that generally require more advanced and prolonged treatment. Risk factors associated with the development of epilepsy include young age, refractory seizures, tuberculoma, cortical involvement, epileptiform discharges, and residual lesions. Treatment of CNS tuberculosis is based on early initiation of appropriate anti-tuberculous drugs, antiseizure medications, and correction of associated predisposing factors. Finally, further research into the mechanisms of seizures and the development of epilepsy in CNS tuberculosis could help improve management of these conditions.

Neurosyphilis presenting as autoimmune limbic encephalitis: A case report and literature review

RATIONALE

Neurosyphilis presenting as limbic encephalitis (LE) is an important differential diagnosis of autoimmune LE (ALE) defined by Graus in 2016. However, data on the clinical differences and similarities between neurosyphilis presenting as LE and ALE are limited. Herein, we report neurosyphilis presenting as ALE that fulfilled the main items of the Graus ALE criteria. Moreover, a literature review of neurosyphilis presenting as LE was performed.

PATIENT CONCERNS

A 66-year-old Japanese man developed nonconvulsive status epilepticus. He presented with progressive personality change and working memory deficits within 3 months prior to admission. A hyperintense lesion localized in the bilateral medial temporal area was observed on T2-weighted fluid-attenuated inversion recovery brain magnetic resonance imaging. Cerebrospinal fluid analysis showed mild pleocytosis and the presence of oligoclonal band. However, in-house assays did not detect antineuronal antibodies. Electroencephalogram showed lateralized rhythmic delta activity in the right temporal area. The serum and cerebrospinal fluid serological and antigen tests for syphilis had positive results.

DIAGNOSIS

ALE was initially suspected based on the patient's symptoms and ancillary test findings that fulfilled the Graus ALE criteria. However, based on the positive confirmatory test results for syphilis, a diagnosis of neurosyphilis was eventually made.

INTERVENTION

The patient received intravenous midazolam, oral levetiracetam, and lacosamide to control nonconvulsive status epilepticus. In addition, he was treated with intravenous benzylpenicillin at a dose of 24 million units/day for 14 days.

OUTCOMES

The patient's cognitive function relatively improved after antibiotic treatment. However, he presented with persistent mild working memory deficit, which was evaluated with the Wechsler Adult Intelligence Scale, 3rd edition. Therefore, on day 103 of hospitalization, he was transferred to another hospital for rehabilitation and long-term care due to limitations in performing activities of daily living.

LESSONS

The present case was diagnosed with neurosyphilis presenting as ALE, but meanwhile, in most case, neurosyphilis presenting as LE developed at a slower progressive rate, and it had a broader or restricted involvement on brain MRI than ALE based on the literature review. Therefore, an appropriate differential diagnosis of LE can be obtained by identifying clinical differences between the 2 conditions.

Status Epilepticus and Neurosyphilis: A Case Report and a Narrative Review

Neurosyphilis is a rare but life-threatening complication of syphilis that can develop even decades after the primary infection and can be unrecognized. Seizures and status epilepticus (SE) may represent the first manifestation in a previously undiagnosed syphilitic patient. We present an exemplification case of a new onset refractory status epilepticus caused by neurosyphilis and we reviewed the existing literature. We selected all studies reporting cases of SE in the context both of patients with a known diagnosis of syphilis and as the first manifestation of neurosyphilis. We identified 50 patients, mostly composed of immunocompetent, middle-aged males. Thirty-nine patients (83%) presented a new onset SE. A history of subtle and rapidly progressive mood and/or cognitive impairment suggesting a limbic encephalitis-like presentation was frequently observed. Focal frontal or temporal SE was reported in 26. Brain MRI frequently showed T2/FLAIR hyperintensities widely involving the medial temporal structures and the frontal lobes. This review should increase the clinician’s awareness of neurosyphilis as a possible etiology of a new onset SE of unknown etiology, especially in the context of a “limbic encephalitis”-like clinical presentation. Prompt recognition and treatment for neurosyphilis partially or completely reverse neurologic sequelae, changing the natural history of the disease.

Neurologic Complications of Tuberculosis

PURPOSE OF REVIEW

This article describes the current epidemiology, common clinical characteristics, and up-to-date evidence-based approaches to the diagnosis and management of the most common neurologic complications of tuberculosis (TB): tuberculous meningitis, intracranial tuberculoma, and spinal TB.

RECENT FINDINGS

Central nervous system (CNS) TB remains common and associated with significant mortality and neurologic sequelae worldwide. Human immunodeficiency virus (HIV) co-infection is strongly associated with both the development of and mortality due to CNS TB. Strongyloides co-infection is associated with reduced CNS inflammation and improved outcomes in the setting of tuberculous meningitis. Stroke remains a common complication of tuberculous meningitis, and emerging evidence suggests aspirin may be used in this context. Although a recent nucleic acid amplification test has demonstrated suboptimal sensitivity in the diagnosis of CNS TB, emerging diagnostic techniques include cell-free DNA, peripheral blood microRNA, metagenomic next-generation sequencing, and advanced imaging techniques, but these are not yet well validated. CNS TB is associated with high mortality even with current treatment regimens, although novel, promising strategies for treatment are under investigation, including a combination of IV isoniazid and ethambutol and high-dose rifampicin.

SUMMARY

TB can affect the nervous system in various ways and is associated with high mortality. Diagnosis remains challenging in endemic settings, with empiric treatment often initiated without a definitive diagnosis. Furthermore, optimal treatment regimens remain uncertain because current treatment for all forms of CNS TB is extrapolated from trials of tuberculous meningitis whereas the role of steroids in people with HIV and tuberculous meningitis remains controversial.

Limbic encephalitis: Experience of a moroccan center

OBJECTIVES

Histologically defined as an inflammation-degeneration of limbic structures, limbic encephalitis (LE) is a rare disease and often difficult to diagnose particularly in institutions with limited access to laboratory tests such as antineuronal antibodies or HSV-PCR, and functional imaging. We aimed to describe the demographic, clinical, paraclinical, and etiological features of LE, as well as its medium-term prognosis in Moroccan patients.

MATERIALS AND METHODS

We collected retrospectively all patients diagnosed with LE in the Department of Neurology of the University Hospital Hassan II of Fez (Morocco) between September 2008 and December 2016. We analyzed their demographic features, clinical manifestations, magnetic resonance imaging and laboratory findings, etiologies, and medium-term prognoses.

RESULTS

We included 22 men and 9 women aged 14-76 years (mean age: 45.8 years). In 64.5% of cases, the onset of symptoms was acute. The clinical manifestations included generalized status epilepticus (16.1%), confusional syndrome (29%), epileptic seizures (38.7%), psychiatric disorders (48.4%), and memory disorders (45.2%). The nonlimbic symptoms were nuchal stiffness (22.6%), headaches (9.7%), fever (61.3%), vesicular rash (3.2%), and language disorders (6.5%). The different etiologies found were herpes simplex virus (6.5%), syphilis (16.1%), tuberculosis (3.2%), varicella (3.2%), paraneoplastic autoimmune LE (22.6%), anti-NMDA-R LE (6.5%), and sarcoidosis (3.2%). We found 12 cases (38.7%) of LE without definite etiology and with an incomplete diagnostic workup. The medium-term clinical course includes a complete remission in 45.2% of cases and partial remission in 45.1% of cases. The different sequelae were temporal lobe epilepsy (9.7%), anterograde amnesia (16.1%), and severe cognitive impairment (19.4%). The mortality rate was 9.7% (3 patients).

CONCLUSION

Our study shows a wide diversity of etiologies of LE in Morocco with essentially an acute mode of onset of symptoms.