Information
Editors
TimoErkinjuntti
MaijaKoivu
Curable Causes of Memory-Related Symptoms and Diseases
Essentials
- Identify curable causes of memory-related symptoms and diseases.
- Treat these patients before their memory function and information processing are permanently impaired.
Depression
- See .
- Memory-related symptoms associated with depression are usually mild: concentration and attention are impaired, intervening stimuli become more disturbing, the working memory has a reduced tolerance to loading, susceptibility to disturbances increases, and performance in memory tests becomes irregular. Depression may, however, also be associated with more severe symptoms of memory function and information processing, but these rarely reach the stage seen in dementia, where the symptom picture is extensive and eventually leads to helplessness (so-called pseudodementia).
- In depression with severe memory symptoms, the following features differing from dementia are often seen:
- a history of mental symptoms or disorders
- the beginning of symptoms can often be defined
- the symptoms are of short duration and they progress rapidly
- the patient's insight into the condition and his/her emotional sensitivity are pronounced
- there are ”I don't know” answers and selective memory gaps including both fresh and old matters
- hints are of help and recognition is often normal, no significant problems in delayed recall.
- Trial of therapy should be started as soon as there is a suspicion of depression or other mood disorder.
Hypothyroidism
- Memory symptoms may in the elderly disguise other symptoms of hypothyroidism .
- Slowness of cognitive processing, difficulties in learning new things and impairment of executive functioning may occur.
Hyper- and hypocalcaemia
- Serum calcium concentration may be only slightly increased even if the patient has a severe impairment of memory function and information processing. Ionised calcium is a better marker of the body's calcium balance.
- The prevalence of hyperparathyroidism in the elderly is about 3%.
- An increase in serum parathyroid hormone concentration is a sign of parathyroid adenoma.
- Some patients will benefit from surgery, and osteoporosis associated with the disease will be concomitantly treated.
- Manifestations of hypoparathyroidism include, in addition to impaired memory function and information processing, also epileptic seizures, ataxia, and muscle spasms.
Vitamin B12 deficiency
- Symptoms of impaired memory function and information processing have been found in 25% of patients.
- Vitamin B12 deficiency causes difficulties in visuospatial perception and abstract thinking. Additionally, mood changes (agitation, mania, depression) as well as psychotic symptoms may occur alongside memory problems.
- Symptoms may precede changes in blood tests or appear without any changes in blood tests.
- Diagnosis: determination of vitamin B12 as holotranscobalamin
- Concentration < 20 pmol/l suggests B12 deficiency.
- Concentration 20-50(-70) pmol/l: possible B12 deficiency
- As further investigation, determination of plasma homocysteine or of the more specific methylmalonate, or a therapeutic trial with vitamin B12 (intramuscular or oral). The impact of the trial must be documented.
- Treatment initially with vitamin B12 injections daily and maintenance therapy at 1-3-month intervals
- Oral administration with dose 1 mg/day may also be applied (1% is absorbed through passive diffusion independent of intrinsic factor). Even then the initial treatment is recommended to be given as injections.
Vitamin B1 (thiamine) deficiency
- Thiamine deficiency can cause Wernicke's syndrome, which includes at least 2 of the following:
- ocular findings (e.g. nystagmus or gaze paresis)
- cerebellar findings (e.g. ataxia or dysdiadochokinesia)
- mental symptoms (decreased level of consciousness or mild to moderate anterograde and retrograde memory disturbance)
- imbalanced diet according to patient history, nausea and vomiting in pregnancy, sequela of bariatric surgery, severe gastroenteritis or alcoholism.
- Dosage of thiamine
- In a confusional state and in alcohol withdrawal 100-250 mg i.v. once daily before starting sugar-/carbohydrate-rich diet
- In diagnosed or suspected Wernicke's syndrome 200 mg i.v. every 8 hours until the patient's condition is settled or restored Neurological Disorders and Alcohol.
Niacin (nicotinic acid, vitamin B3) deficiency
- Deficiency leads to pellagra (dementia, dermatitis and diarrhoea).
- Initially symptoms of the central nervous system: fatigue, anxiety and irritability
- Later on, psychotic symptoms and cognitive impairment develop, and, additionally, rigidity and decreased level of consciousness may occur.
- Cognitive symptoms resemble those of thiamine deficiency.
- Treatment: niacin 150 mg once daily, in severe cases 1 g × 3-4 parenterally
Folate deficiency
- The role of the deficiency in the development of memory symptoms is unclear.
- Symptoms resemble the symptom picture caused by vitamin B12 deficiency
- It is recommended to correct the potential deficiency by replacement therapy.
- Folic acid 1 mg initially 3 times daily and later on once daily for a period of at least 6 months.
Chronic subdural haematoma
- The majority of these patients are elderly.
- One-half of them present with symptoms related to memory function and information processing or with confusion.
- The trauma may have occurred several months earlier. Some of the patients may not be aware of any head injury.
- Bilateral subdural haematoma in particular does not necessarily include unilateral neurological symptoms, nor is it always visible in the CT scan.
- Treatment consists of neurosurgical removal of the haematoma; however, if the haematoma is less than 1 cm in thickness, monitoring of resorption is frequently sufficient.
Normal-pressure hydrocephalus (NPH)
- Partial disruption in the circulation of the cerebrospinal fluid. The condition may develop as a delayed complication of meningitis, encephalitis, subarachnoidal haemorrhage, brain injuries, and brain surgery. In some cases the cause is unclear.
- NPH symptoms include progressive symptoms related to memory and information processing, apractic gait (jerky gait composed of small steps as if the ”template for walking” were lost but the motor function is preserved), urinary incontinence. Increased muscle tone, i.e. rigidity and spasticity may also occur.
- Memory symptoms manifest as memory lapses and reduced application of acquired information.
- Surgical shunting can relieve the memory symptoms in some patients, particularly if the symptoms have not lasted for long. It is advisable to also take a brain biopsy during the shunt operation to examine for the possibility of concurrent Alzheimer's disease.
- Improvement of memory symptoms may take place over a period of several months.
Infections
- Even today, cases of memory disease caused by tertiary syphilis are found .
- Impairment of memory function and information processing may also be associated with
- sequelae of suppurative or tuberculous meningitis
- immunodeficiency.
- The Borrelia burgdorferi spirochete may cause chronic encephalitis and impairment of memory function and information processing (see Encephalitis).
Uraemia
- In addition to memory impairment, personality changes, apathy, flapping tremor, muscle twitching, and spasms are seen in uraemia .
Liver diseases
- The accumulation of toxic substances in the brain is a generally recognized cause of hepatic encephalopathy .
- The blood ammonia concentration is increased.
- Symptoms include impaired cognitive function as well as impaired consciousness and flapping tremor, among others.
Chronic pulmonary diseases
- These may cause cerebral insufficiency related to oxygen deprivation and carbon dioxide retention; however, only an extremely severe pulmonary disease may cause actual extensive impairment of memory and information processing which would hamper the everyday life.
Hypoglycaemia
- Repeated and prolonged hypoglycaemic attacks may lead to permanent memory and information processing symptoms .
Tumours
- Symptoms related to malignant tumours (e.g. gliomas and metastases) usually progress rapidly; thus the patient should be examined with appropriate urgency.
- Symptoms related to benign tumours may progress insidiously, which can cause difficulties in their differentiation from Alzheimer's disease, psychiatric conditions, or other disorders. In such cases, the tumour often resides in the frontal lobe or falx.
- With malignant tumours, a memory disease may also be expressed as a paraneoplastic phenomenon. This is most often associated with lung or breast cancer.
Medications and abuse of drugs
- The pharmacokinetics and pharmacodynamics of pharmaceuticals change with age, which predisposes to cognitive adverse effects.
- Anticholinergic drugs
- Inhibit the functions of acetylcholine receptors (the cholinergic network is important for the state of mental alertness, attentiveness and memory).
- In addition to memory problems, confusion and agitation may occur.
- Particularly persons with organic brain disease are susceptible to adverse effects.
- Anticholinergic drugs include: tricyclic antidepressants, conventional antipsychotics, scopolamine, in particular first-generation antihistamines, and most drugs used for urinary leakage.
- Alcohol
- Intoxication and hangover reduce alertness and ability to concentrate.
- Alcohol causes cognitive problems.
- Thiamine deficiency is a potential additional cause.
- Long-term impacts of alcohol
- Executive functioning is reduced more than memory functions or linquistic skills.
- Reduced problem-solving capacity and ability for abstract thinking
- Imaging studies reveal atrophy in the cerebellum and frontal lobe.
- Alcohol abstinence for at least 3 months before memory investigations
- Drugs of abuse
- Most drugs negatively affect the working memory and episodic memory.
- Cannabis: cognitive flexibility and learning ability are reduced, ability to stay alert is impaired
- Amphetamine: cognitive function is slowed down, delayed recall and verbal fluency become worse
- Opioids: recall becomes worse, cognitive flexibility is impaired
Others
- See also Delirium in the elderly .