Charlotte has developed some clinically focused flash cards that help explain neuroanatomy & head and neck anatomy in an applied form to support medical undergraduates with integrating their knowledge. These images and their associated notes can also be found on our instagram page too.
Hydrocephalus is an excessive accumulation of cerebrospinal fluid (CSF) in the brain . It causes the ventricular system to enlarge, which typically causes increased intracranial pressure. If it is not treated, it can lead to permanent brain damage.
Symptoms of hydrocephalus can include headache , vomiting , blurred vision , poor
balance, urinary incontinence, seizures, and a rapid increase in head size in babies (since the fontanelles of the skull have not yet fused)
Hydrocephalus can be congenital or acquired. Congenital hydrocephalus can be caused by spina bifida or maternal infections in pregnancy (mumps and rubella).
The pathophysiology of hydrocephalus can be categorised as:
Increased CSF production (e.g. choroid plexus papilloma)
Decreased CSF absorption (e.g. meningitis, subarachnoid haemorrhage, normal pressure hydrocephalus)
CSF obstruction (e.g. congenital aqueduct stenosis, tectal plate glioma, colloid cyst)
It is treated with shunt surgery or endoscopic third ventriculostomy (ETV)
There are a number of dopaminergic pathways in the brain
The following pathways are clinically relevant to to the action and side effects of antipsychotics, for the treatment of Schizophrenia. These are D2 antagonists that act by reducing dopamine levels.
Transmits dopamine from the midbrain (VTA) to the ventral striatum. It includes the nucleus accumbens (which is associated with motivations, emotions and rewards). This is thought to be responsible for the positive symptoms of Schizophrenia, which are reduced with antipsychotic use.
Transmits dopamine from the midbrain (VTA) to the prefrontal cortex. Hypofunction of this pathway is thought to be responsible for the negative symptoms in Schizophrenia.
Transmits 80% of the brains dopamine from the pars compacta of the substantia nigra to the caudate nucleus and putamen. Antipsychotics that reduce dopamine can induce extrapyramidal side effects (similar to the pathophysiology of Parkinson’s disease).
Transmits dopamine from the hypothalamus to the pituitary gland. Dopamine in this pathway acts to inhibit prolactin. Blockade of D2 receptors by antipsychotics causes hyperprolactinaemia, and can result in breast enlargement, galactorrhoea, reduced libido and erectile dysfunction.
Migraine a common type of primary headache
It typically causes a severe, unilateral, throbbing headache, and is associated with nausea, vomiting, photophobia and phonophobia. It can last up to 72 hours.
Migraines can occur with and without aura (neurological symptoms). Auras are most commonly visual disturbances and can include blind spots, flashes and scotoma . However, auras may also consist of paraesthesia, weakness and vertigo.
Common triggers for a migraine are tiredness, stress, alcohol, menstruation, the combined oral contraceptive pill,
hunger, dehydration, cheese , chocolate, red wine citrus and bright lights. It 3 times more common in women.
Focal seizures are seizures arising from a focal area within one hemisphere of the brain. They can progress to generalised seizures
Frontal lobe focal seizures may show signs including head or leg movement, abnormal posturing and Jacksonian march (a phenomenon in which the seizure starts at the distal part of a limb and progresses towards the ipsilateral face, like a “march”)
Parietal lobe focal seizures often consist of sensory symptoms like tingling, pain and temperature changes
Occipital lobe focal seizures involve visual phenomena such as colours, flashes of light and scotoma
Temporal lobe seizures are the most common of the focal seizures. Its signs can be remembered by “HEAD”’
- Hallucinations (which can be auditory, olfactory or gustatory)
- Emotions or an epigastric rising sensation
- Automatisms (non-purposeful repetitive behaviours e.g. lip smacking)
- Déjà vu
Alzheimer’s disease is the most common form of dementia. It has a slower and more insidious onset than many other types of dementia.
Macroscopically, the brain in Alzheimer’s disease exhibits generalised cerebral cortex atrophy (especially of the medial temporal lobe), widening of sulci, enlarged ventricles (a compensatory mechanism), and atrophy of the hippocampus .
The hippocampus is critical for the formation of new memories, so it is unsurprising that patients with Alzheimer’s often have deficits in short term memory.
Other early features include word finding difficulties , decision making difficulties, apathy and mood changes.
Later, patients may exhibit behavioural and psychological symptoms (like agitation and aggression), delusions, sleep disorders, physical frailty, incontinence, weight loss and communication difficulties.
Addison’s disease is a rare disorder of the adrenal glands. It is also known as primary adrenal insufficiency. It can be life threatening.
Damage to the adrenal glands (usually autoimmune) results in insufficient production of steroid hormones (including cortisol and aldosterone).
To try and maintain homeostasis, the hypothalamus stimulates the pituitary gland to release more ACTH to stimulate the adrenal glands to produce more steroid hormones.
This also has the effect of increasing melanocyte-stimulating hormone, which results in the characteristic bronze skin pigmentation in Addison’s disease.
Other signs and symptoms include weight loss, low blood pressure, hypoglycaemia, GI disturbance (nausea, vomiting, abdominal pain, constipation), muscle weakness, increased thirst, fatigue and low mood. Treatment involves lifelong replacement of the steroid hormones