This chapter provides an overview of neurological problems like epilepsy and encephalitis. International League Against Epilepsy (ILAE) defines seizure as a transient occurrence of signs or symptoms due to abnormal, excessive or synchronous neuronal activity. At least two unprovoked or reflex seizures occur more than 24 hours apart. One unprovoked or reflex seizure and a probability of further seizure similar to the general recurrence risk (at least 60%) after two unprovoked seizures occur over the next 10 years. Epilepsy can be confirmed with the history and seizure semiology like duration, one side or both, precipitating factor, predisposing factors and type of seizure. Diagnostic approach includes metabolic profile, urine amino acid, organic acid toxicology, electroencephalogram for interictal abnormalities, differentiating pseudoseizure, and video EEG for recording the event with EEG. Drug selection depends on seizure type. A case of acute encephalitis syndrome (AES) is defined as a person of any age, at any time of year with the acute onset of fever and at least one of: change in mental status, new onset of seizures. \"Enteroviruses\" are the most common causes of viral meningitis. The onset is variable and may have several days of fever, anorexia and general malaise and signs of infections, such as pharyngitis, conjunctivitis and myositis. Varicella-zoster virus (VZV) may cause central nervous system (CNS) infection in close temporal relationship with chickenpox. The most common manifestation of CNS involvement is cerebellar ataxia, and the most severe is acute encephalitis. Cytomegalovirus (CMV) infection of the CNS may be part of congenital infection or disseminated disease in compromised hosts, but it does not cause meningoencephalitis in normal infants and children. Cerebrospinal fluid findings are discussed along with meningitis. Electroencephalogram is a sensitive means to detect viral encephalitis. Slow waves, spikes, or spike-wave discharges, including PLEDS, that localize to the temporal regions increase the probability of HSV encephalitis. Polymerase chain reaction (PCR) can be used to detect DNA viruses, including CMV, VZV, EBV, and the JE virus. Some RNA viruses, such as rabies virus, HIV, enteroviruses, and certain arboviruses, can be detected reliably by reverse transcription PCR.