Bacterial meningitis resulting in visual impairment and panhypopituitarism

Less known aspects of central hypothyroidism: Part 1 - Acquired etiologies

Central hypothyroidism (CH) is a rare cause of hypothyroidism. CH is frequently overlooked, as its clinical picture is subtle and includes non-specific symptoms; furthermore, if measurement of TSH alone is used to screen for thyroid function, TSH concentrations can be normal or even above the upper normal reference limit. Indeed, certain patients are at risk of developing CH, such as those with a pituitary adenoma or hypophysitis, those who have been treated for a childhood malignancy, have suffered a head trauma, sub-arachnoid hemorrhage or meningitis, and those who are on drugs capable to reduce TSH secretion.

Prospective investigation of pituitary functions in patients with acute infectious meningitis: is acute meningitis induced pituitary dysfunction associated with autoimmunity?

Previous case reports and retrospective studies suggest that pituitary dysfunction may occur after acute bacterial or viral meningitis. In this prospective study we assessed the pituitary functions, lipid profile and anthropometric measures in adults with acute bacterial or viral meningitis. Moreover, in order to investigate whether autoimmune mechanisms could play a role in the pathogenesis of acute meningitis-induced hypopituitarism we also investigated the anti-pituitary antibodies (APA) and anti-hypothalamus antibodies (AHA) prospectively. Sixteen patients (10 males, 6 females; mean ± SD age 40.9 ± 15.9) with acute infectious meningitis were included and the patients were evaluated in the acute phase, and at 6 and 12 months after the acute meningitis. In the acute phase 18.7% of the patients had GH deficiency, 12.5% had ACTH and FSH/LH deficiencies. At 12 months after acute meningitis 6 of 14 patients (42.8%) had GH deficiency, 1 of 14 patients (7.1%) had ACTH and FSH/LH deficiencies. Two of 14 patients (14.3%) had combined hormone deficiencies and four patients (28.6%) had isolated hormone deficiencies at 12 months. Four of 9 (44.4%) hormone deficiencies at 6 months were recovered at 12 months, and 3 of 8 (37.5%) hormone deficiencies at 12 months were new-onset hormone deficiencies. At 12 months there were significant negative correlations between IGF-I level vs. LDL-C, and IGF-I level vs. total cholesterol. The frequency of AHA and APA positivity was substantially high, ranging from 35 to 50% of the patients throughout the 12 months period. However there were no significant correlations between AHA or APA positivity and hypopituitarism. The risk of hypopituitarism, GH deficiency in particular, is substantially high in the acute phase, after 6 and 12 months of the acute infectious meningitis. Moreover we found that 6th month after meningitis is too early to make a decision for pituitary dysfunction and these patients should be screened for at least 12 months. In addition, the occurrence of AHA and APA positivity due to acute infectious meningitis was demonstrated for the first time. Further longer-term prospective investigations need to be carried out on a larger cohort of patients to understand the role of autoimmunity in the pathogenesis of late hypopituitarism after acute infectious meningitis.

Investigation of pituitary functions in patients with acute meningitis: a pilot study

OBJECTIVE

Although long-term pituitary consequences of tuberculous meningitis are well documented in the literature, there have been few case reports of pituitary dysfunction after acute bacterial or viral meningitis. In this preliminary study, we have assessed the pituitary functions in adult patients who had acute bacterial or viral meningitis.

DESIGN AND METHODS

Fourteen patients (8 men, 6 women; mean age 35.3+/-13.3) were included in the study. The diagnosis of bacterial and viral meningitis was proven by clinical findings, cerebrospinal fluid (CSF) examination, gram staining, and blood and CSF cultures. Pituitary functions were evaluated ranging from 6 to 48 months (mean 20 months) after acute meningitis. GH deficiency was investigated by the GHRH+arginine stimulation test.

RESULTS

Four of 14 patients (28.6%) had isolated GH deficiency. In GH-deficient patients, the earliest duration was 6 months and the latest duration was 48 months after the diagnosis of acute meningitis. Three of the GH-deficient patients had acute bacterial meningitis and 1 patient had acute viral meningitis. Pituitary magnetic resonance imaging revealed normal pituitary gland in the patients with GH deficiency.

CONCLUSIONS

This is the first systematic study evaluating the anterior pituitary function long term after the diagnosis of acute meningitis. Based on the present study, it is tempting to speculate that pituitary dysfunction is a more common sequel of acute bacterial or viral meningitis than hitherto reported. Studies with high numbers of patients are warranted to ascertain the prevalence of meningitis-induced hypopituitarism.