Biological Assessment of Patients with Psychiatric Symptoms

Biological Assessment of Patients with Psychiatric Symptoms د.وليد عزيز العميدي

Biological alterations and abnormalities can underlie psychiatric symptoms and influence their occurrence. A variety of studies are used clinically to identify such alterations and abnormalities in patients.
MEASUREMENT OF BIOGENIC AMINES AND PSYCHOTROPIC DRUGS
A. Altered levels of biogenic amines and their metabolites occur in some psychiatric conditions .
B. Plasma levels of some antipsychotic and antidepressant agents are measured to evaluate patient compliance or to determine whether therapeutic blood levels of the agent have been reached.
C. Laboratory tests also are used to monitor patients for complications of pharmacotherapy.
1. Patients taking the mood stabilizer carbamazepine (Tegretol) or the antipsychotic agent clozapine (Clozaril) must be observed for blood
1. abnormalities, such as agranulocytosis (very low, e.g., <2,000, white blood cell count
2. Liver function tests are used in patients being treated with carbamazepine and valproic acid (mood stabilizers(
3. Thyroid function and kidney function tests should be used in patients who are being treated with the mood stabilizer lithium. Patients taking lithium can develop hypothyroidism and, occasionally, hyperthyroidism.
4. Lithium levels also should be monitored regularly because of the drug s narrow therapeutic range .

DEXAMETHASONE SUPPRESSION TEST (DST)
A. In a normal patient with a normal hypothalamic-adrenal-pituitary axis, dexamethasone, a synthetic glucocorticoid, suppresses the secretion of cortisol. In contrast, approximately one half of patients with major depressive disorder have a positive DST (i.e., this suppression is limited or absent(
B. There is some evidence that patients with a positive DST (indicating reduced suppression of cortisol) will respond well to treatment with antidepressant agents or to electroconvulsive therapy .
C. The DST has limited clinical usefulness. Positive findings are not specific; non-suppression is seen in conditions other than major depressive disorder.
These disorders include schizophrenia, dementia, Cushing disease, pregnancy, anorexia nervosa or severe weight loss, and endocrine disorders. Nonsuppression is also seen with use, abuse, and withdrawal of alcohol and antianxiety agents.


TESTS OF ENDOCRINE FUNCTION
A. Thyroid function tests are used to screen for hypothyroidism and hyperthyroidism, which can mimic depression and anxiety, respectively.
1. Physical symptoms of hypothyroidism include fatigue, weight gain, edema, hair loss, and cold intolerance.
2. Physical symptoms of hyperthyroidism include rapid heartbeat ("palpitations"), flushing, fever, weight loss, and diarrhea.
B. Patients with depression may have other endocrine irregularities, such as positive DST (see above), reduced response to a challenge with thyrotropin releasing hormone, and abnormalities in growth hormone, melatonin, and gonadotropin.
C. Psychiatric symptoms are associated with endocrine and enzyme disorders, such as Addison disease (hypocortisolism), Cushing disease)hypercortisolism), and acute intermittent porphyria.
1-Addison disease
a. Physical signs and symptoms include hyperpigmentation of the skin, particularly in skin creases, low blood pressure, pain, fainting, hypoglycemia, diarrhea, and vomiting.
b. Psychiatric symptoms include fatigue, depression, psychosis, and confusion.
2-Cushing disease
a. Physical signs and symptoms include round "moon" face, bruising, purple striae on the skin, sweating, facial hair, hypertension, fat on the back of the neck ("buffalo hump"), and a positive DST.
b. Psychiatric symptoms include elevated mood, psychosis, anxiety, and depression.
3- . Acute intermittent porphyria
a. Physical signs and symptoms include elevated porphobilinogen, severe pain, abdominal cramps, diarrhea and vomiting, seizures, cardiacarrhythmias, flushing, and purple discoloration of urine.
b. Psychiatric symptoms include paranoid delusions and hallucinations, depression, and anxiety.







NEUROIMAGING AND ELECTROENCEPHALOGRAM STUDIES
Specific Test or Measure Uses and Characteristics
Computed tomography (CT) Identifies anatomically based brain changes (e.g., enlarged brain ventricles) in cognitive disorders, such as Alzheimer disease, as well as in schizophrenia
Nuclear magnetic resonance imaging (NMRI) Identifies demyelinating disease (e.g., multiple sclerosis)
Shows the biochemical condition of neural tissues without exposing the patient to ionizing radiation
Positron emission tomography (PET) or
functional
MRI (fMRI) Localizes areas of the brain that are physiologically active during specific tasks by characterizing and measuring metabolism of glucose in neural tissue
Measures specific neurotransmitter receptors
Requires use of a cyclotron
Single photon emission tomography (SPECT) Obtains similar data to PET or fMRI but is more practical for clinical use because it uses a standard gamma camera rather than a cyclotron
Electroencephalogram (EEG) Measures electrical activity in the cortex
Is useful in diagnosing epilepsy and in differentiating delirium (abnormal EEG) from dementia (often normal EEG)
Shows, in schizophrenic patients, decreased alpha waves, increased theta and delta waves, and epileptiform activity

Evoked EEG (evoked potentials) Measures electrical activity in the cortex in response to tactile, auditory, sound, or visual stimulation
Is used to evaluate vision and hearing loss in infants and brain responses in comatose and suspected brain dead patients

NEUROPSYCHOLOGICAL TESTSA. Neuropsychological tests are designed to assess general intelligence, memory, reasoning, orientation, perceptuomotor performance, language function, attention, and concentration in patients with suspected neurologic problems, such as dementia and brain damage.
Test Uses
Halstead-Reitan battery To detect and localize brain lesions and determine their effects
Luria-Nebraska neuropsychological
battery To determine left or right cerebral dominance
To identify specific types of brain dysfunction, such as dyslexia
Bender Visual Motor Gestalt Test
To evaluate visual and motor ability through the reproduction of designs


B. In such patients, the Folstein Mini-Mental State Examination (Table 5-3) is designed to follow improvement or deterioration and the Glasgow Coma Scale
(Table 5-4) is designed to assess level of consciousness by rating patient responsiveness.
Folstein Mini-Mental State Examination
Skill Evaluated Sample Instructions to the Patient Maximum Scorea
Orientation Tell me where you are and what day it is. 10
Language Name the object that I am holding. 8
Attention and concentration Subtract 7 from 100 and then continue to subtract 7s. 5
Registration Repeat the names of these three objects. 3
Recall After 5 min, recall the names of these three objects 3
Construction Copy this design. 1
aMaximum total score = 30; total score <25 suggests cognitive problems; total score <20 suggests significant impairment.


Glasgow Coma Scale (GCS)
Number of Points Best Eye-Opening
Response (E) Best Verbal
Response (V) Best Motor
Response (M)
1 No eye opening No verbal response No motor response
2 Opens eyes in response
to painful stimulus Makes incomprehensible
sounds Shows extension to
painful stimulus
3 Opens eyes in response to
a verbal command Speaks using inappropriate
words Shows flexion to
painful stimulus
4 Opens eyes spontaneously Makes confused verbal response Withdraws from
painful stimulus
5 - Is oriented and can converse Localizes a source of pain
6 - - Obeys commands

aMaximum total score on the GCS = 15; lowest possible score = 3; a GSC score of <12 indicates mild, 9–12 indicates moderate, and <9 indicates severe neurologic impairment. The reported score is commonly broken down into components (e.g., E2 V1 M3 = GCS 6).

OTHER TESTS
A. Drug-assisted interview
1- Administration of a sedative, such as amobarbital sodium ("the Amytal interview"), prior to the clinical interview may be useful in determining whether organic pathology is responsible for symptomatology in patients who exhibit certain psychiatric disorders or malingering.
2- Sedatives can relax patients with conditions such as dissociative disorder, conversion disorder, and other disorders involving high levels of anxiety and mute psychotic states. This will allow patients to express themselves coherently during the interview.

B. Sodium lactate administration.
Intravenous (IV) administration of sodium lactate can provoke a panic attack in susceptible patients and can thus help to identify individuals with panic disorder. Inhalation of carbon dioxide can produce the same effect.

C. Galvanic skin response a component of the "lie detector"test)The electric resistance of skin (galvanic skin response) varies with the patient s psychological state.Higher sweat gland activity, seen with sympathetic nervous system arousal (e.g., when lying) results in decreased skin resistance and a positive test. However, innocent but anxious people may also have positive tests (false positives)