Group B Streptococcus Meningitis in an Adult Woman with Type 2 Diabetes and Ethmoid Roof Defect. Impact on "frontal" Cognitive Functions

Background: Community-acquired bacterial meningitis in adults represents one of the most severe infectious diseases worldwide with potentially life-threatening medical complications. Several infectious agents can cause acute meningitis. Although group B Streptococcus is more prevalent in newborns, infection can also lead to meningitis in older adults, particularly those with underlying health issues.

Case description: A 53-year-old woman with a body mass index of 28.7 kg/m², type 2 diabetes mellitus, and dyslipidaemia presented to the emergency department of Santa Maria della Stella Hospital (Orvieto, Italy) with confusion, low-grade fever, echolalia, and hyperglycaemia. Computed tomography scans of the brain revealed a hypodensity in the left anterior frontal lobe and an osteodural defect of the rhinobase. Meningitis was suspected and empiric broad-spectrum antibiotic therapy with corticosteroids and insulin were administered while the results of the cerebrospinal fluid analysis confirmed the diagnosis of group B Streptococcus meningitis. Repeat imaging at 48 hours revealed enlargement of the hypodense lesion. The frontal assessment battery indicated deficits in executive functions. Prompt treatment led to rapid clinical improvement. Following the restoration of euglycemic status and hemodynamic stabilization, a follow-up magnetic resonance imaging confirmed the ischaemic lesion and showed cerebrospinal fluid in the sella turcica. The patient was then transferred to neurorehabilitation.

Conclusions: The complex interactions among multiple risk factors resulted in an atypical clinical case of group B Streptococcus meningitis, which was promptly treated with empiric antibiotic therapy to mitigate neurocognitive deficits.

Learning points: Group B Streptococcus can cause meningitis in adults with poorly controlled type 2 diabetes mellitus and should be promptly treated with empiric broad-spectrum antibiotics.An osteodural defect of the ethmoid roof together with idiopathic intracranial hypertension may result in empty sella turcica and CSF rhinorrhoea, promoting the dissemination of the pathogen.Meningitis patients with pre-existing diabetic cerebral vasculopathy may develop cerebrovascular complications and cognitive impairments.