The Potential Role of Infections in Attention- Deficit Hyperactivity Disorder.

Attention deficit hyperactivity disorder ADHD is a behavioral disorder which mostly affects children in the age group of six to eleven years. The disorder affects boys more than girls. Although difficult to assess in infancy and toddlerhood, signs of ADHD may begin to appear as early as age of two or three, but the symptom picture changes as adolescence approaches. Many symptoms, particularly hyperactivity, diminish in early adulthood. However, impulsivity and inattention problems remain with upto 50% of ADHD individuals through their adult life. Recently there have been studies on correlation between ADHD and bacterial and viral infections in brain. This review focuses on possible role of various viruses and certain bacterias in development of ADHD in children.

Cryptococcal granulomas in an immunocompromised HIV-negative patient.

Disseminated cryptococcosis usually occurs in immunocompromised individuals with defective cell-mediated immunity, most commonly seen with HIV infection. We present a case of disseminated cryptococcosis in an HIV-negative male patient who presented with headache, fever, altered sensorium of short duration and multiple cutaneous lesions. An emergency CT scan of the head showed multiple intracranial and intraventricular granulomas. Routine laboratory investigations were within the normal range. A CSF examination revealed capsulated yeasts on India ink and a culture yielded cryptococcus neoformans. A cryptococcal antigen test by latex agglutination kit was positive. A biopsy revealed multiple capsulated yeasts cells in the cutaneous lesions, which were consistent with cryptococcus neoformans. The patient was successfully treated with Amphotericin B and Fluconazole with regression of cranial and cutaneous lesions.

Computer tomographic findings of the brain in HIV-patients at Ramathibodi Hospital.

OBJECTIVE: To determine the underlying cause of the brain lesions in adult HIV patients referred for CT scan at Ramathibodi Hospital and to evaluate accuracy of CT for the diagnosis of the brain lesion. MATERIAL AND METHOD: Data from first CT scan of the brain of 195 adult HIV patients at Ramathibodi Hospital were reviewed The final diagnoses from medical records were assessed followed by CSF analysis, pathological report, and therapeutic treatment. The accuracy of the CT brain was evaluated using sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). RESULTS: One hundred ninety five adult seropositive patients for HIV underwent CT scan of the brain, 59% were HIV encephalopathy (HIVE), 22% toxoplasmosis, 9% cryptococcoma, 5% tuberculous meningitis, 4% tuberculoma, 3% progressive multifocal leukoencephalopathy (PML), 2% lymphoma, and 1% normal. In non-specified causes (from CT scan), 33% were meningitis, 4% cerebritis, and 5% infarction. CT was found to have high sensitivity, specificity, PPV, and NPV for toxoplasmosis (92%, 96%, 86%, and 98%, respectively). CONCLUSION: HIV encephalopathy was the most common finding of adult HIV brains. Toxoplasmosis was the most common opportunistic parenchymal brain lesion in adult HIV brains. CT was the modality of choice for diagnosis and exclusion of toxoplasmosis, but it cannot determine the cause of disease showing meningitis pattern.

Invasive aspergillosis of paranasal sinuses: findings from the Sudan

The Sudan is endemic for Aspergillus species, especially Aspergillus flavus. They commonly invade the paranasal sinuses, but massive invasion of the brain in immunocompetent patients is rare. To describe the clinical presentation and MRI findings in immunocompetent patients with massive paranasal aspergillosis with extensive invasion of the brain. Four patients, who are negative for HIV and other immunocompromizing disorders were studied in this article. Two females 55 and 25 year old, 2 males 29 and 62 year old were described. All cases showed extensive invasion of the paranasal sinuses and the adjacent structures. Invasive paranasal Aspergillosis can affect immunocompetent patients and the commonest organism is Aspergillus flavus

Cerebral blastomycosis: a case report.

Blastomycosis is a chronic systemic fungal infection characteristically affecting the skin and lungs. Involvement of the central nervous system (CNS) is unusual, with cases generally presenting with meningitis, and rarely as intracranial mass lesion and solitary or multiple abscesses. Only two cases of intracranial extra-axial blastomycosis have been reported from India, and we report the third case, which presented as meningioma in a 23-year old female.

Cryptococcus gattii fungemia: report of a case with lung and brain lesions mimicking radiological features of malignancy

A 64-year-old apparently immunocompetent white man developed lung and brain lesions of disseminated cryptococcosis. The radiologic features mimicked those of lung cancer metastatic to the central nervous system. C. gattii was recovered from cultures of bronchoalveolar lavage fluid, brain biopsy, and blood. The same fungus was recovered from pulmonary and brain specimens at autopsy. Serum and cerebrospinal fluid cryptococcal antigen tests were diagnostic in our case and should be included in the diagnostic evaluation of unexplained pulmonary and cerebral lesions. A literature search showed few reports of fungemia by this species of Cryptococcus, contrasting to C. neoformans.

Homem branco de 64 anos, aparentemente imunocompetente, desenvolveu lesões pulmonares e cerebrais por criptococose disseminada. Os achados radiológicos foram similares àqueles encontrados em pacientes com câncer de pulmão e metástase no sistema nervoso central. C. gattii foi isolado de cultivos de lavado broncoalveolar, biópsia cerebral e sangue. O mesmo fungo foi encontrado em fragmentos pulmonares e cerebrais obtidos da autópsia. Testes de antígeno no soro e no líquido cefalorraquidiano foram diagnóstico no nosso caso e devem ser incluídos na avaliação diagnóstica de lesões pulmonares e cerebrais indefinidas. Pesquisa na literatura mostrou poucos relatos de fungemia por esta espécie de Cryptococcus, contrastando com C. neoformans.

Disseminated nocardiosis in an elderly patient presenting with prolonged pyrexia: Diagnosis by thyroid abscess culture.

We report a case of nocardiosis in an immunosuppressed elderly patient who presented with prolonged pyrexia. Nocardia asteroides was isolated from the thyroid, with CT scan evidence of dissemination to the brain, abdomen and lungs. The patient succumbed to illness despite aggressive therapy. Autopsy could not be performed. To the best of our knowledge, this is the first reported case from India, on Nocardia asteroides affecting the thyroid tissue.

Neuroaspergillosis in an immunocompetent patient.

Aspergillosis of the central nervous system (CNS) is an uncommon infection, mainly occurring in immunocompromised patients. We report a case of neuroaspergillosis caused by Aspergillus flavus in an immunocompetent patient presenting as a space-occupying lesion of the CNS. The patient was responding favorably to voriconazole at the time of this report.

Pathogenesis and pathology of brain abscess.

Brain abscess continues to be a serious medical problem with increasing incidence despite advances in diagnostic and surgical methods, and advent of new antibiotics. This is due to increase in immune suppressed individuals, opportunistic pathogens and resistance to antibiotics. The morbidity, mortality and long term sequelae of brain abscess like cognitive impairment and poor neurological outcome are due to persistent release of proinflammatory mediators by activated microglia, astrocytes and infiltrating inflammatory cells, along with disruption of blood brain barrier. Anti-inflammatory drugs along with specific antimicrobial agents help in minimizing damage to the adjacent brain parenchyma. Identification of microorganisms in the aspirated material or the excised specimen help decide the optimal antimicrobial therapy. Prompt examination of smear and meticulous culture techniques to identify aerobes, anerobes, mycobacteria, actinomycetes, parasites and fungi are of utmost importance in choosing antibiotics. Histology complements culture and plays a key role especially in specific infections. Use of appropriate histochemical stains along with tissue reaction helps in diagnosis. The route of spread, the type and virulence of the organism, thickness of the capsule, location and number of abscesses in the brain, and immune status of the host are important determinants of outcome. Identification of microorganisms and insights into pathogenesis allow appropriate therapeutic interventions to improve outcome.

Aspergilloma of the brain: an overview.

Fungal infections of the central nervous system (CNS) are almost always a clinical surprise. Their presentation is subtle, often without any diagnostic characteristics, and they are frequently mistaken for tuberculous meningitis, pyogenic abscess, or brain tumor. Granulocytopenia, cellular and humoral mediated immune dysfunction are predisposing factors to the development of CNS infections in immunosuppressed patients. Aspergillus fumigatus is the most common human pathogen in the genus Aspergillus. Maxillary sinusitis of dental origin or the lungs are the most common sites of primary Aspergillus infection. Infection reaches the brain directly from the nasal sinuses via vascular channels or is blood borne from the lungs and gastrointestinal tract. Single or multiple abscess formation with blood vessel invasion leading to thrombosis is a characteristic feature of Aspergillosis on neuropathologic examination. Aspergillosis should be considered in cases manifesting with acute onset of focal neurologic deficits resulting from a suspected vascular or space-occupying lesion especially in immunocompromised hosts. Aspergillosis is diagnosed on direct examinations and culture, however the diagnosis of aspergillosis of the CNS is difficult. Diagnosis of an intracranial mass lesion is best confirmed with a computed tomography or magnetic resonance imaging of the head with or without intravenous contrast. Aggressive neurosurgical intervention for surgical removal of Aspergillus abscesses, granulomas, and focally infracted brain; correction of underlying risk factors; Amphotericin B combined with flucytosine and treatment of the source of infection should form the mainstay of the management. Off late Liposomal Amphotericin B was found to be more effective and safe than conventional Amphotericin B in the management of Apergillus infections Only with a high index of suspicion, an aggressive approach to diagnosis, and rapid vigorous therapy may we hope to alter the clinical course in this group of patients.

Disseminated Cryptococcosis in a Patient with Pituitary Cushing's Disease

Disseminated cryptococcosis mainly occurs in patients with cell-mediated immunity disorders. A case of disseminated cryptococcosis, in a patient with pituitary Cushing's disease, is reported. Cultures of blood, cerebrospinal fluid (CSF) and aspirates of a skin lesion all grew Cryptococcus neoformans. Despite antifungal treatment, with amphotericin-B, the patient died within 3 weeks.

Cerebral chromoblastomicosis--a rare case report of cerebral abscess and brief review of literature--a case report.

A rare case of Cerebral Chromomycosis caused by chromogenic fungus Cladosporium trichoides in a 35 year old male with classical presentation of cerebral abscess is being presented. The case report lays emphasis on the histological diagnosis of chromogenic fungus in the wall of the abscess cavity, surgically removed from a well delineated circumscribed lesion in the frontal lobe of the cerebrum. The causative fungus could be detected even in unstained paraffin sections. The diagnosis could be made only after surgical removal and histopathological examination. The mycological culture could not be made as the material was received in formaldehyde fixative. The unique features of the case is its recurrence free uneventful survival five years after surgical excision. This is probably the fifth reported case of cerebral chromomycosis from India and first of its type from arid zone of Rajasthan.

Herpes simplex encephalitis: a diagnostic and therapeutic reapprisal.

Herpes Simplex Encephalitis (HSE) appears to be underdiagnosed in India, though viral encephalitides constitutes an important entity with significant morbidity. With an upsurge in AIDS, HSE may perhaps emerge as an important opportunistic infection in future. We discuss the clinical features and laboratory evaluation of nine cases of HSE seen in the last 12 years at our center. Diagnosis was established by brain biopsy in one, virological studies in six and at autopsy in three. Immunocytochemically viral antigens could be localized in 4 biopsied/autopsied brain tissue and in CSF cells on a cytospin preparation in one. This has facilitated rapid diagnosis in our cases. Virus isolation was successful in two. Three subjects were treated with acyclovir and all survived with variable morbidity. Four patients expired and none of them had received any specific antiviral drugs. Rapid diagnosis and early treatment with acyclovir has been highlighted.

Cryptococcal intracerebral mass lesions associated with cryptococcal meningitis.

12 patients with cryptococcal intracerebral mass lesions associated with cryptococcal meningitis are reported. There were 6 males and 6 females with a mean age of 41 years. Most of them presented with symptoms and signs of meningitis initially without focal neurological signs. Computed tomography revealed single or multiple, well or poorly marginated hypodense lesions without perilesional edema, except 1 case which had marked edema, with or without ring enhancement. One case had small hyperdense, diffuse, enhanced nodules. New lesions or progression of the existing lesions occurred during medical therapy in some patients. The clinical manifestations of patients with intracranial mass lesions did not significantly differ from patients without mass lesions, but the mortality was higher (50% vs 29%).

Detection of rabies virus in different tissues of experimentally infected mice at preclinical and postclinical stages of the disease.

Rabies fixed virus (CVS) was passaged 10 times in mice by intramuscular (im) route followed by experimental inoculation of the titrated virus in 4 groups of mice with the dose of 0.1 ml of 1000 mouse (LD50 0.03 ml) using intracerebral (ic), intravenous (iv), intramuscular (im), intraocular (io), and intranasal (in) routes respectively. No marked variation in clinical signs due to variation of routes could be detected. Involvement of brain with io route could be detected even in preclinical stage. Although the virus could be detected in the postclinical stage in all the tissues under study (brain, skin, salivary gland and corneal impression), with io and ic routes spread of the virus was observed in comparatively higher concentrations.