The central nervous system comprises of two types of cells; neurons and neuroglial cells. Glial cells are the support cells that serve a number of important functions. Three types of neuroglia comprise the mature nervous system, which are ependymal cells, microglia, and macroglia. The macroglia are of two types oligodendrocytes and astrocytes. Microglia are the neuroglial cells that serve the function of phagocytosis since they are derived from the hematopoietic stem cells and share properties with tissue macrophages. They remove the cellular debris from the site of injury or normal cellular turnover by performing scavenger function.

Arnold-Chiari malformation type II is one of the congenital hindbrain abnormalities that leads to a disruption of the relationship between different hindbrain structures. It is characterized by congenital hydrocephalus, herniation of cerebellar tonsils into the pinal canal with an enlarged 4th ventricle, spina bifida associated with myelomeningocele, and various levels of denervation atrophy of the muscles of the lower limb. The association of type II Arnold-Chiari with myelomeningocele carries importance from an etiological perspective, forming the basis of CSF escape theory.

Neuroanatomically, the frontal lobe is the largest lobe of the brain lying in front of the central sulcus. It is divided into 3 major areas defined by their anatomy and function. They are the primary motor cortex, the supplemental and premotor cortex, and the prefrontal cortex. Damage to the primary motor, supplemental motor, and premotor areas lead to weakness and impaired execution of motor tasks of the contralateral side. The inferolateral areas of the dominant hemisphere are the expressive language area (Broca area, Brodmann areas 44 and 45), to which damage will result in a non-fluent expressive type of aphasia.

Nissl body is a neuron-specific cellular structure. It is composed of rough endoplasmic reticulum and fine granules. The rough endoplasmic reticulum contains free ribosomes, and are the hub of protein synthesis. When these substances are exposed to a cresyl violet solution, they show selective-staining by turning purple-blue. In pathologic processes, they may undergo chromatolysis.

Lamotrigine does not significantly increase risk of birth defects during pregnancy.

Acoustic neuroma/vestibular schwannoma is a benign slow-growing tumour. The clinical picture of the child suggests neurofibromatosis type 1 (NF1), with cafe-au-lait spots and axillary and inguinal freckling.

Epilepsy is a common paediatric neurologic disorder characterized by seizures of varying frequency and intensity. There are many childhood or infantile epilepsy syndromes that can be categorized as benign epilepsy syndromes as the child suffering from these usually outgrows them after reaching a certain age, and they do not lead to significant cognitive or physical impairment. Some of these may not need any treatment. Such benign epilepsy syndromes include benign rolandic epilepsy, Panayiotopoulos syndrome, Gastaut type-idiopathic childhood occipital epilepsy, and idiopathic photosensitive occipital lobe epilepsy. West syndrome, also called infantile spasms, is a serious infantile epileptic encephalopathy, characterized by multiple clusters of myoclonic spasms, and regression of the previous normally attained milestones. It is associated with severe cognitive and physical impairment, often leading to life long disability.

Myelomeningocele is the most common type of open neural tube defect and a serious central nervous system disorder associated with significant morbidity. It is also called open spina bifida since the dura, and arachnoid matter herniates through the defect in the vertebral column. The commonest association is the decreased folate levels during early pregnancy. The alpha-fetoprotein levels are raised in the amniotic fluid. CSF leak is a common presentation with associated macrocephaly and hydrocephaly. Prenatal surgical repair is linked to a better prognosis.

Fragile X syndrome is a genetic syndrome associated with neuro-developmental problems such as learning disabilities and cognitive impairment, with many affected children having mild to moderate intellectual disability. About a third of children have features of autism spectrum disorder and ADHD which affects their communication skills and social interactions. As such, affected individuals usually have delayed speech development and poor nonverbal skills such as gaze aversion. Symptoms tend to worsen with age into adolescence as the demands on their intellect becomes greater. Pre-mutation carriers, who posses smaller genetic repeat expansions, have been found to be associated with some neurodevelopment and other medical problems.

The clinical presentation of the boy suggests the involvement of the right frontal lobe.Psychiatric or behavioural disturbances secondary to frontal lobe lesions exhibit lateralisation. The lesions of the left hemisphere are associated with depression, especially if the lesion involves the dorsolateral portion of the prefrontal cortex. Whereas, lesions of the right hemisphere are associated with impulsivity, disinhibition, and aggression, as it is the case with the child in question.Presenting symptoms of lobar dysfunctions:- Frontal lobe: Contralateral hemiplegia, impaired problem solving, disinhibition, and lack of initiative. Broca’s aphasia and agraphia suggest the involvement of the dominant hemisphere.- Temporal lobe: Wernicke’s aphasia (dominant hemisphere involvement), homonymous upper quadrantanopia and auditory agnosia (non-dominant hemisphere involvement).- Parietal lobe: Anosognosia, dressing apraxia, spatial neglect and constructional apraxia are observed when the non-dominant hemisphere is involved. Gerstmann’s syndrome is observed when the dominant hemisphere is involved.- Occipital lobe: Visual agnosia, visual illusions and contralateral homonymous hemianopia.