The prevalence of hypocholesterolemia in the elderly ranges between 2% to 36%, depending on specific cutoff levels and age range investigated. Alerting physicians to hypocholesterolemia may benefit some of their patients who take cholesterol-lowering drugs and decrease the rate of their emergency room visits. Critical illness
In the setting of critical illness, low cholesterol levels are predictive of clinical deterioration, and are correlated with altered cytokine levels. Causes
Possible causes of low cholesterol are:
statins
hyperthyroidism, or an overactive thyroid gland
adrenal insufficiency
liver disease
malabsorption (inadequate absorption of nutrients from the intestines), such as in celiac disease
malnutrition
abetalipoproteinemia - a rare genetic disease that causes cholesterol readings below 50 mg/dL. It is found mostly in Jewish populations. hypobetalipoproteinemia - a genetic disease that causes cholesterol readings below 50 mg/dL
manganese deficiency
Smith–Lemli–Opitz syndrome
Marfan syndrome
leukemias and other hematological diseases

Diagnosis
Classification
According to the American Heart Association in 1994, only total cholesterol levels below 160 mg/dL or 4.1 mmol/L are to be classified as "hypocholesterolemia". However, this is not agreed on universally and some put the level lower. References


== External links ==
Logopenic progressive aphasia (LPA) is a variant of primary progressive aphasia. It is defined clinically by impairments in naming and sentence repetition. It is similar to conduction aphasia and is associated with atrophy to the left posterior temporal cortex and inferior parietal lobule. It is suspected that an atypical form of Alzheimers disease is the most common cause of logopenic progressive aphasia.Although patients with the logopenic variant of PPA are still able to produce speech, their speech rate may be significantly slowed due to word retrieval difficulty. Over time, they may experience the inability to retain lengthy information, causing problems with understanding complex verbal information. Some additional behavioral features include irritability, anxiety and agitation.Compared to other subtypes of primary progressive aphasia, the logopenic variant has been found to be associated with cognitive and behavioral characteristics. Studies have shown that patients with the logopenic variant perform significantly worse on tests of calculation than other primary progressive aphasia patients. Several logopenic variant patients, especially those with Alzheimers disease pathology, have also been found to perform poorly on memory tasks.Logopenic progressive aphasia is caused by damage to segregated brain regions, specifically the inferior parietal lobe and superior temporal regions. Difficulties in naming are produced from the thinning of the inferior parietal lobe. Damage to the dorsal pathways creates language deficiency in patients that is characteristic of logopenic progressive aphasia. See also
Aphasia
Dementia
Early-onset Alzheimers disease

References
Further reading
Harciarek M, Kertesz A (September 2011). "Primary progressive aphasias and their contribution to the contemporary knowledge about the brain-language relationship". Neuropsychol Rev. 21 (3): 271–87.