Injuries to the peroneal nerve can cause numbness, tingling, pain, weakness and foot drop. The branches of the common peroneal nerve innervate and control the muscles in the legs that lift the ankle and toes upward (dorsi flexion).

The trigeminal nerve is responsible for the sensory innervation of the head, and the muscles of mastication. The nerve is divided into three branches, the ophthalmic nerve (V1) the mandibular nerve (V2) and the maxillary nerve (V3) which all exit the skull through their respective foramina. An easy way to remember these foramina is with the following mnemonic:Standing Room Only, for V1-V3 respectivelyV1- Superior orbital FissureV2- foramen RotundumV3 foramen Ovale

Becker’s muscular dystrophy is a disease characterised by progressive weakness and wasting of the skeletal and cardiac muscles. It is inherited and primarily affects males.

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

The most likely cause of microcephaly in an asymptomatic 3-year-old child is congenital rubella syndrome.Microcephaly is defined as head circumference > two standard deviations below the mean.The causes of microcephaly include:- Genetic disorders: Down syndrome, Edward syndrome, Patau syndrome, Williams syndrome, Angelman syndrome, and Rett syndrome.- Infective: Meningitis, toxoplasmosis, CMV, rubella, varicella, HIVand Zika.- Acquired causes: Severe brain malformations, neurodegenerative diseases, hypoxic-ischemic injury, infarction, antenatal exposure to drugs, alcohol, and other toxins. Severe malnutrition and uncontrolled phenylketonuria in the mother are other causes of microcephaly in children.- Craniosynostosis- Neurometabolic disorders- Early non-accidental trauma- Fanconi anaemia- Other causes include: Familial and nonfamilial nonsyndromic microcephalyMost children with microcephaly have one or several associated symptoms:- Developmental delay- Seizures- Visual abnormalities- Short stature

The vignette describes an infant with a sustained post-delivery brachial plexus injury that does not improve with time. MRI is the most appropriate intervention to assess the injury and evaluate the treatment options.

Non Epileptic attack disorder, also known as psychogenic non epileptic seizures, is a condition characterised by episodes of abnormal movement and behaviours that resemble seizures , but are not caused by electrical activity changes in the brain. It is believed that the disorder is caused by the brain’s response to overwhelming or stressful situations. In Jamila’s case, triggering conditions for her episodes may have been the absence of her mother, and the stress of her upcoming examinations. A diagnosis of generalised epilepsy is unlikely because this would require abnormal movement in all 4 limbs during an episode and a longer period of semi consciousness after. Cataplexy can also be ruled out as it does not involve a loss of consciousness which we see in Jamila’s case. Vasovagal syncope does not correspond with the history as there was no evidence of simultaneous collapse and responsiveness coupled with colour change and near spontaneous recovery when supine. A complex partial seizure may be possible in Jamila’s case, however the history of long duration, her eyes being tightly shut and the differences in presentation between the two episodes makes it less likely.

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.

Cluster headaches present with unilateral severe headache that may be associated with ipsilateral cranial autonomic symptoms including| lacrimation, rhinorrhoea, ophthalmic injection, and occasionally, Horner syndrome (ipsilateral miosis, ptosis, and facial anhidrosis).

The patient’s clinical presentation is highly suggestive of Charcot–Marie–Tooth syndrome.It is a hereditary sensory and motor neuropathy. It is also the commonest cause of inherited peripheral neuropathy. The lower motor neuron signs are usually mild in childhood, the age of onset is very variable, and the distal weakness can take years to progress. It is not fatal and does not affect the normal life expectancy.

Absence epilepsy is the most common type of generalized childhood epilepsies. It is mainly idiopathic, but 10-40% of the cases have a positive family history. It is characterized by frequent absence seizures and periods of unconsciousness. The hallmark of absence epilepsy on EEG is the bilaterally synchronous 2–4 Hz spike and wave discharges (SWDs). The average age of onset is around 4-8 years, being more prevalent among girls. Treatment resistance is not common.

Autism is a neurodevelopmental disorder characterized by difficulties with social interaction, language delays, and some repetitive behaviours. Autism may be associated with some dysmorphic facial features, including macrocephaly, which denotes an abnormally large head. Macrocephaly is usually most observable during early childhood. The other features mentioned are not found to be associated with autism.

The sympathetic chain lies posterior to the parietal pleura. During a thorascopic sympathectomy, this structure will have to be divided. The intercostal vessels lie posteriorly. They may be damaged with troublesome bleeding but otherwise are best left alone as the deliberate division will not improve surgical access.The sympathetic nervous system:The cell bodies of the preganglionic efferent neurones lie in the lateral horn of the grey matter of the spinal cord in the thoracolumbar regions.The preganglionic efferents leave the spinal cord at levels T1-L2. These pass to the sympathetic chain.Lateral branches of the sympathetic chain connect it to every spinal nerve. These postganglionic nerves will pass to structures that receive sympathetic innervation at the periphery.Sympathetic chains:These lie on the vertebral column and run from the base of the skull to the coccyx.Clinical correlation:Interruption of the head and neck supply of the sympathetic nerves will result in an ipsilateral Horner’s syndrome.For the treatment of hyperhidrosis, the sympathetic denervation can be achieved by removing the second and third thoracic ganglia with their rami. Removal of T1 will cause a Horner’s syndrome and is therefore not performed.In patients with vascular disease of the lower limbs, lumbar sympathectomy may be performed, either radiologically or (more rarely now) surgically. The ganglia of L2 and below are disrupted. Care should be taken to preserve the L1 ganglion. If it is removed in male patients, ejaculation may be compromised.

The CSF picture in bacterial meningitis has the following characteristics: several polymorphs, cells, protein that is maximum 5g/l, a few lymphocytes and glucose that accounts for the two thirds of the blood level.

The blood-brain barrier (BBB) is a term used to describe the unique properties of the microvasculature of the central nervous system (CNS). CNS vessels are continuous nonfenestrated vessels, but also contain a series of additional properties that allow them to tightly regulate the movement of molecules, ions, and cells between the blood and the CNS.Blood vessels are made up of two main cell types: Endothelial Cells (ECs) that form the walls of the blood vessels, and mural cells that sit on the abluminal surface of the EC layer. The properties of the BBB are largely manifested within the ECs, but are induced and maintained by critical interactions with mural cells, immune cells, glial cells, and neural cells, which interact in the neurovascular unit.Astrocytes are a major glial cell type, which extends polarized cellular processes that ensheath either neuronal processes or blood vessels.This includes regulating the contraction/dilation of vascular smooth muscle cells surrounding arterioles as well as PCs surrounding capillaries. Astrocytes have been identified as important mediators of BBB formation and function because of the ability of purified astrocytes to induce barrier properties.

Juvenile myoclonic epilepsy is an epilepsy syndrome characterized by myoclonic jerks, generalized tonic-clonic seizures (GTCSs), and sometimes, absence seizures. The seizures of juvenile myoclonic epilepsy often occur when people first awaken in the morning. Seizures can be triggered by lack of sleep, extreme fatigue, stress, or alcohol consumption. Onset typically occurs around adolescence in otherwise healthy children. The causes of juvenile myoclonic epilepsy are very complex and not completely understood. Mutations in one of several genes, including the GABRA1 and the EFHC1 genes, can cause or increase susceptibility to this condition. Although patients usually require lifelong treatment with anticonvulsants, their overall prognosis is generally good.

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.

While the cause for Bell’s palsy is still under debate, it is observed that Bell’s palsy is often preceded by a viral infection. Bell’s Palsy:Bell’s palsy (idiopathic facial palsy) is an acute unilateral lower motor neurone palsy. It typically occurs two weeks after viral infection such as Epstein–Barr, herpes simplex, herpes zoster or mumps. A careful assessment may suggest an alternative aetiology for the acute onset of weakness, e.g. acute otitis media, Lyme disease, hypertension. Causes:In childhood, Bell’s palsy is probably a post-infectious (i.e. immune-mediated) phenomenon, while in adults, there is increasing evidence that the majority of cases follow reactivation of previous HSV infection. Management:The prognosis is generally good in childhood with full recovery in the majority. However, permanent weakness is observed in around 5%. Steroids and acyclovir may have some benefit in adults with recent onset of weakness, but the evidence of the treatment benefit is much less convincing in childhood. Exposure keratitis is an important complication and children should be managed with eye drops and taping of the eyelid at night until recovery is complete.

Benign neonatal sleep myoclonus is a condition characterised by neonatal onset myoclonic jerks during NREM. Characteristic for this disorder is the absence of electroencephalographic findings.

A vasovagal episode or vasovagal syncope is the most common form of reflex syncope. Reflex syncope is a general term used to describe types of syncope resulting from a failure in autoregulation of blood pressure, and ultimately, in cerebral perfusion pressure resulting in transient loss of consciousness. The mechanisms responsible for this are complex and involve both depression of cardiac output as well as a decrease in vascular tone. Other types of reflex syncope include carotid sinus syncope and situational syncope, for instance, cough or micturition syncope. Vasovagal syncope may be triggered by pain or emotional upset, although frequently a specific trigger cannot be identified.