Description of Medical Condition Any opacity of the lens, either localized or generalized. Single largest cause of blindness in the world, blinding an estimated 17 million people. • Types include: – Age-related (“senile”) — over 90% – Congenital -1/250 newborns, 10-38% of childhood blindness – Toxic/nutritional – Systemic disease associated e.g., myotonic dystrophy, atopic dermatitis – Metabolic — diabetes (accelerated sorbitol pathway), hypocalcemia, Wilson disease – “Complicated” — secondary to associated eye disease, e.g., uveitis (juvenile rheumatoid arthritis, sarcoid, etc.). Also secondary to occult tumor (melanoma, retinoblastoma). – Trauma — heat (infrared), electrical shock, radiation, concussion, perforating eye injuries, intraocular foreign body System(s) affected: Nervous Genetics: • Age related cataract has …
[ Continue Reading... ]Description of Medical Condition This is the most common cause of peripheral nerve compression. The median nerve is compressed as it traverses the carpal tunnel in the wrist and hand. The tunnel is composed of the carpal bones dorsally and the transverse carpal ligament ventrally. It contains flexor tendons and the median nerve. Symptoms tend to affect the dominant hand but over half the patients experience bilateral symptoms. System(s) affected: Musculoskeletal, Nervous Genetics: Unknown, however a familial type has been reported Incidence/Prevalence in USA: Most common entrapment neuropathy. Most recent estimates of prevalence indicate that the disorder occurs in 346/100,000 population. Predominant age: 40 to 60 Predominant sex: Female > Male …
[ Continue Reading... ]Description of Medical Condition Malignant neoplasm in the breast. Breast cancers are classified as noninvasive (in situ) or invasive (infiltrating) with approximately 70% of all breast cancers possessing a component of invasion. System(s) affected: Skin/Exocrine, Pulmonary Gastrointestinal, Musculoskeletal, Nervous Genetics: • Only 20% of patients have a significant family history of breast cancer. This predisposition tends to be autoso-mal dominant with maternal lineage. • Recent studies have revealed families with breast cancer susceptibility genes including BRCA1 and BRCA2. Family history suggestive of breast cancer susceptibility genes include multiple first and second degree relatives with early breast cancer diagnosis and the presence of ovarian cancer. Approximately 1 in 400 U.S. women will …
[ Continue Reading... ]Epilepsy is common, affecting up to 2% of the population. Thus, it is inevitable that most doctors, whether neurologists, surgeons, general practitioners or hospital physicians, will at some stage have to manage a patient with epilepsy. People with epilepsy may have an exacerbation in their seizures due to a concomitant medical condition or its treatment, a person without epilepsy may have an acute symptomatic seizure during an acute illness, or a patient may develop epilepsy associated with a medical condition. Even though a patient’s seizures may be well controlled at baseline, an untimely seizure during a systemic disturbance may impact adversely on outcome, predispose the patient to infections and cause metabolic …
[ Continue Reading... ]Seizures may occur in uraemic encephalopathy, dialysis disequilibrium syndrome and dialysis encephalopathy. In addition, renal insufficiency and dialysis may both have effects on anti-epileptic drug pharmacokinetics. Renal impairment can alter the fraction of anti-epileptic drug absorbed, volume of distribution, protein binding and renal drug clearance. Renal impairment may alter the gastric pH, cause small intestinal bacterial overgrowth, gastrointestimal tract oedema and impaired gastrointestinal motility. These factors may cause reduced ionization of some drugs and reduce drug absorption. The volume of distribution of drugs may be increased in patients with end-stage renal failure, resulting in lower total plasma levels. However, protein binding of acidic drugs may be significantly reduced in renal impairment; …
[ Continue Reading... ]The liver is the principal organ of drug metabolism. Some drugs are absorbed from the gut, delivered to the liver and undergo first-pass metabolism prior to reaching the systemic circulation. Metabolism of these drugs is significantly affected by hepatic vascular supply; if hepatic blood flow is reduced, first-pass metabolism is decreased and more drug reaches the systemic circulation. Other drugs reach the systemic circulation before being delivered to the liver for metabolism; hepatocyte function is more important than the blood supply for their metabolism. Cytochrome P450 enzymes are involved in Phase I metabolism (non-synthetic metabolism which includes oxidation, reduction and hydrolysis). There is substantial genetic polymorphism within these enzymes, and people …
[ Continue Reading... ]Metabolic disturbances are a common cause of seizures, even in patients without epilepsy. In most cases, acute metabolic derangements causing seizures are potentially reversible. Seizures due to metabolic derangements are often refractory to anti-convulsant medications; correction of the underlying abnormality is required. Hyponatraemia is the most common electrolyte disturbance encountered in clinical practice. It is a common side-effect of many drugs, including carbamazepine and oxcarbazepine. Oxcarbazepine seems to be associated with a higher incidence of hyponatraemia than carbamazepine, 30% vs. 14% in one study. Risk factors for the development of hyponatraemia are age >40, female gender, use of drugs associated with hyponatraemia, psychiatric illness and surgery. It may also be due …
[ Continue Reading... ]The incidence of epilepsy is highest in patients >75 years, with a point prevalence of 1.5%, and as the population ages doctors will treat increasing numbers of older patients with epilepsy. Treatment of epilepsy in older patients is complicated by alterations in pharmacodynamics and pharmacokinetics, metabolic derangements, presence of multiple co-morbid diseases, polypharmacy and psychosocial factors. The aetiology of epilepsy in older patients differs from that of young people; the most frequent cause being cerebrovascular disease. Seizures are usually partial in onset and may be mistaken for recurrent strokes or TIAs, which may lead to unnecessary investigations and inappropriate treatment. In addition, morbidity and mortality are higher in elderly patients with …
[ Continue Reading... ]The goal of epilepsy treatment is ‘no seizures, no side-effects’. Monotherapy is preferred if possible, because of greater patient compliance with medications, better quality of life, more favourable adverse effect profile, lack of drug interactions and cost issues. However, many patients with epilepsy will require more than one anti-epileptic drug, and many patients will also be on other medications for co-morbid conditions. This means that a large proportion of people with epilepsy are at risk of drug interactions. When new anti-epileptic drugs are undergoing trials, they are almost invariably tested as add-on therapy, meaning that they are initially licensed only as add-on treatment rather than as monotherapy. Drug interactions may be …
[ Continue Reading... ]There are a number of other neurological conditions in which anti-epileptic drugs are used. These may occur in patients with co-existing epilepsy. It may be useful in these patients to use an anti-epileptic drug which has efficacy for both conditions to avoid polypharmacy and drug interactions. Migraine affects approximately 15% and epilepsy 2% of the population at any one time. As both are so common it is likely that some patients will have both epilepsy and migraine simply by chance; however, the literature suggests a clear association between the two. One theory behind their association is that both conditions are channelopathies. In some cases, the underlying aetiology may be a clear …
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