Neuropsychiatric Aspects of Parasitic Infections-A Review.

Neuropsychiatric disorders, ranging from mild cognitive impairment to frank psychosis, have been associated with certain parasitic infections. The parasite may cause damage to the central nervous system in several ways: as a space-occupying lesion (neuro-cysticercosis), alteration of neurotransmitters (toxoplasmosis), generation of the inflammatory response (trypanosomiasis, schistosomiasis), hypovolemic neuronal injury (cerebral malaria), or a combination of these. Certain drugs like quinacrine (mepacrine), mefloquine, quinolone, and interferon alpha which are used to treat these parasitic infections can further cause neuropsychiatric adverse effects. This review summarizes the major parasitic infections that are associated with neuropsychiatric disorders and the pathogenesis involved in their processes. A high index of suspicion for parasitic diseases, especially in endemic areas, should be kept in patients presenting with neuropsychiatric symptoms. A multidimensional approach to identification of the offending parasite using serological, radiological, and molecular tests is required not only to ensure proper and prompt treatment of the primary parasitic infection but also to improve the prognosis of patients by complete resolution of neuropsychiatric symptoms.

A study on neurcognitive disorders and demographic profile of neurocysticercosis patients.

BACKGROUND: Neurocysticercosis is a common cerebral parasitic infestation, caused due to pork tapeworm infection the infestations risks parallels the socio-economic status, personal hygiene and education. The effect of NCC was assessed in neurocognition. OBJECTIVE: To study demographic characteristics and neurocognitive domains of patients with Neurocysticercosis. METHODS: Neurocysticercosis diagnosed patients by CT, MRI and LAMP tests. MMSE score was measured for assessment. RESULTS: MMSE score were reduced in majority of the patients. In attention was the most common deficit found. Repeat MMSE assessment done in 6 patients showed an improvement of scores post therapy. CONCLUSION: Cognitive involvement is common in NCC and is a major cause of morbidity.

Identification of Taenia solium DNA by PCR in blood and urine samples from a tertiary care center in North India.

BACKGROUND: NCC is a neglected zoonotic disease with high endemicity and disease burden. Neurocysticercosis is a frequent cause of seizures in endemic countries. Early diagnosis and therapy helps in reducing morbidity and DALYs (daily adjusted life years) lost. Definite diagnosis still relies on neuroimaging identification of scolex or by histopathological examination. Molecular method such as PCR (Polymerase Chain Reaction) is an emerging modality to supplement or complement these Gold standard methods. AIM: To determine the utility of PCR in detecting Taenia Solium DNA in NCC patients. METHODS: A total of 100 blood samples of cases of NCC and 50 control blood samples, 58 urine samples of NCC cases and 24 control samples were collected. Repetitive element PTsol9 of the Taenia Solium was targeted. RESULTS: The sensitivity and specificity of PCR in blood samples was 57% and 94%, while sensitivity and specificity in urine samples was 64% and 87%. CONCLUSION: PCR assay can be used as an adjunct for the diagnosis of NCC especially in ambiguous cases, this is relatively rapid and non-invasive diagnostic modality.

Newer magnetic resonance imaging techniques in neurocysticercosis.

INTRODUCTION: The definitive diagnosis of neurocysticercosis continues to be challenging. We evaluate the role of newer magnetic resonance imaging techniques including constructive interference in steady state, susceptibility-weighted imaging, arterial spin labelling and magnetic resonance spectroscopy in the diagnosis of neurocysticercosis. AIMS AND OBJECTIVES: To study the utility of newer magnetic resonance imaging sequences in the diagnosis of neurocysticercosis. PATIENTS AND METHODS: Eighty-five consecutive patients with neurocysticercosis attending a tertiary care hospital and teaching centre in northern India were included in the study. The diagnosis of neurocysticercosis was made by the Del Brutto criteria. All patients received treatment according to standard guidelines and were followed at 3-month intervals. The following magnetic resonance sequences were performed at baseline: T1 and T2-weighted axial sequences; T2 fluid-attenuated inversion recovery axial sequences; diffusion-weighted imaging; susceptibility-weighted imaging; pre and post-contrast T1-weighted imaging; heavily T2-weighted thin sections (constructive interference in steady state); arterial spin labelling (n = 19); and magnetic resonance spectroscopy (n = 24). RESULTS: The mean (±SD) age was 29.4 ± 12.9 years and 76.5% were men. Seizures were the commonest symptom (89.4%) followed by headache (24.3%), encephalitis (9.4%) and raised intracranial pressure (9.4%). Scolex could be visualised in 43.7%, 55.5% and 61.2% of neurocysticercosis patients using conventional, susceptibility-weighted angiography and constructive interference in steady state imaging sequences, respectively. Susceptibility-weighted angiography and constructive interference in steady state images resulted in significantly higher (P < 0.01) visualisation of scolex compared to conventional sequences. CONCLUSION: Newer magnetic resonance imaging modalities have a lot of promise for improving the radiological diagnosis of neurocysticercosis.

Sorting out difficulties in immunological diagnosis of neurocysticercosis: Development and assessment of real time loop mediated isothermal amplification of cysticercal DNA in blood.

PURPOSE OF THE STUDY: Among various immunological tests available for diagnosis of neurocysticercosis (NCC), only EITB (Electroimmunotransfer blot for detection of anticysticercal antibodies) had gained widespread acceptance. However EITB is not available widely and is costly (Indian rupees 15,000/- approximately). We evaluated utility of Loop mediated isothermal amplification (LAMP) assay for detection of Taenia solium cox1 gene in blood of patients with NCC. PATIENTS AND METHODS: Current study included 100 consecutive patients of NCC at a tertiary teaching hospital in Northern India. All the patients underwent detailed history and examinations as well as gadolinium enhanced magnetic resonance imaging of brain. LAMP assay was performed in all the patients. The results were compared with 50 controls. RESULTS: LAMP detected Taenia Solium cox1 gene in 74% of all blood samples in patients of NCC.T he overall sensitivity of LAMP assay for detection of cox1 gene was 74% in all patients with NCC, 71.8% in patients with intraparenchymal brain cysts only and 86.7% of patients with extraparenchymal brain cysts with or without intraparenchymal brain cysts. The overall specificity of LAMP assay was 90% in all these three subgroups. The positive predictive value of real time LAMP assay was close to 93% for almost all forms of NCC- both solitary and multiple while negative predictive value ranged from 57 to 64%. CONCLUSION: Real time LAMP assay of blood for detection of Taenia solium cox1 gene appears to be a promising toll for diagnosis of NCC.