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5.8 Neuroimaging

Cardiac Ultrasound Cardiac ultrasound is the visualization of cardiac anatomy by the use of computer-transformed echoes of ultrasound. It is commonly used in the evaluation of mitral valve prolapse. There is an unclear association between mitral valve prolapse and panic attacks and anxiety disorders. R eferences Baron DA, Baron DA, Baron DH. Laboratory testing for substances of abuse. In: Frances RJ, Miller SI, Mack AH, eds. Clinical Textbook of Addictive Disorders. 3 rd ed. NewYork: Guilford; 2011:63. Blumenthal JA, Sherwood A, Babyak MA, Watkins LL, Smith PJ, Hoffman BM, O’Hayer CV, Mabe S, Johnson J, Doraiswamy PM, Jiang W, Schocken DD, Hinderliter AL. Exercise and pharmacological treatment of depressive symptoms in patients with coronary heart disease: Results from the UPBEAT (Understanding the Prognostic Benefits of Exercise and Antidepressant Ther- apy) study. J Am Coll Cardiol. 2012;60(12):1053. Cernich AN, Chandler L, Scherdell T, Kurtz S. Assessment of co-occurring disor- ders in veterans diagnosed with traumatic brain injury. J Head Trauma Rehabil. 2012;27:253. Guze BH, James M. Medical assessment and laboratory testing in psychiatry. In: Sadock BJ, SadockVA, Ruiz P, eds. Kaplan & Sadock’s ComprehensiveTextbook of Psychiatry. 9 th ed. Philadelphia: Lippincott Williams &Wilkins; 2009:995. Kim HF, Schulz PE, Wilde EA, Yudosfky SC. Laboratory testing and imaging studies in psychiatry. In: Hales RE, Yudosfky SC, Gabbard GO, eds. Essentials of Psychiatry. 3 rd ed. Arlington: American Psychiatric Publishing; 2011:15. Meszaros ZS, Perl A, Faraone SV. Psychiatric symptoms in systemic lupus erythe- matosus: A systematic review. J Clin Psychiatry. 2012;73(7):993. Mordal J, Holm B, Mørland J, Bramness JG. Recent substance intake among patients admitted to acute psychiatric wards: Physician’s assessment and on-site urine testing compared with comprehensive laboratory analyses. J Clin Psycho- pharm. 2010;30(4):455. Perez VB, Swerdlow NR, Braff DL, Näätänen R, Light GA. Using biomarkers to inform diagnosis, guide treatments and track response to interventions in psychotic illnesses. Biomark Med . 2014;8:9–14. Roffman JL, Silverman BC, Stern TA. Diagnostic rating scales and laboratory test- ing. In: Stern TA, Fricchione GL, Cassem NH, Jellinek M, Rosenbaum JF, eds. Massachusetts General Hospital Handbook of General Hospital Psychiatry. 6 th ed. Philadelphia: Saunders; 2010:61. Saczynski JS, Marcantonio ER, Quach L, Fong TG, Gross A, Inouye SK, Jones RN. Cognitive trajectories after postoperative delirium. N Engl J Med. 2012;367(1):30. Vannest J, Szaflarski JP, Eaton KP, Henkel DM, Morita D, Glauser TA, Byars AW, Patel K, Holland SK. Functional magnetic resonance imaging reveals changes in language localization in children with benign childhood epilepsy with cen- trotemporal spikes. J Child Neurol. 2013;28(4):435–445. ▲▲ 5.8 Neuroimaging Primary observation of structural and functional brain imaging in neuropsychiatric disorders such as dementia, movement dis- orders, demyelinating disorders, and epilepsy has contributed to a greater understanding of the pathophysiology of neurological and psychiatric illnesses and helps practicing clinicians in dif- ficult diagnostic situations. Neuroimaging methodologies allow measurement of the structure, function, and chemistry of the living human brain. Over the past decade, studies using these methods have pro- vided new information about the pathophysiology of psychiatric disorders that may prove to be useful for diagnosing illness and for developing new treatments. Computer tomographic (CT) scanners, the first widely used neuroimaging devices, allowed assessment of structural brain lesions such as tumors or strokes. Magnetic resonance imaging (MRI) scans, developed next, dis- tinguish gray and white matter better than CT scans do and allow visualizations of smaller brain lesions as well as white matter

abnormalities. In addition to structural neuroimaging with CT and MRI, a revolution in functional neuroimaging has enabled clinical scientists to obtain unprecedented insight into the dis- eased human brain. The foremost techniques for functional neuroimaging include positron emission tomography (PET) and single photon emission computed tomography (SPECT).

Uses of Neuroimaging Indications for Ordering Neuroimaging in Clinical Practice

Neurological Deficits.  In a neurological examination, any change that can be localized to the brain or spinal cord requires neuroimaging. Neurological examination includes mental sta- tus, cranial nerves, motor system, coordination, sensory system, and reflex components. The mental status examination assesses arousal, attention, and motivation; memory; language; visuospa- tial function; complex cognition; and mood and affect. Consultant psychiatrists should consider a workup including neuroimaging for patients with new-onset psychosis and acute changes in men- tal status. The clinical examination always assumes priority, and neuroimaging is ordered on the basis of clinical suspicion of a central nervous system (CNS) disorder. Dementia.  Loss of memory and cognitive abilities affects more than 10 million persons in the United States and will affect an increasing number as the population ages. Reduced mortality from cancer and heart disease has increased life expectancy and has allowed persons to survive to the age of onset of degenerative brain disorders, which have proved more difficult to treat. Depres- sion, anxiety, and psychosis are common in patients with demen- tia. The most common cause of dementia is Alzheimer’s disease, which does not have a characteristic appearance on routine neuro- imaging but, rather, is associated with diffuse loss of brain volume. One treatable cause of dementia that requires neuroimaging for diagnosis is normal pressure hydrocephalus, a disorder of the drainage of cerebrospinal fluid (CSF). This condition does not progress to the point of acutely increased intracranial pres- sure but stabilizes at a pressure at the upper end of the normal range. The dilated ventricles, which may be readily visualized with CT or MRI, exert pressure on the frontal lobes. A gait disorder is almost uniformly present; dementia, which may be indistinguishable from Alzheimer’s disease, appears less con- sistently. Relief of the increased CSF pressure may completely restore gait and mental function. Infarction of the cortical or subcortical areas, or stroke, can produce focal neurological deficits, including cognitive and emotional changes. Strokes are easily seen on MRI scans. Depression is common among stroke patients, either because of direct damage to the emotional centers of the brain or because of the patient’s reaction to the disability. Depres- sion, in turn, can cause pseudodementia. In addition to major strokes, extensive atherosclerosis in brain capillaries can cause countless tiny infarctions of brain tissue; patients with this phenomenon may develop dementia as fewer and fewer neural pathways participate in cognition. This state, called vascular dementia, is characterized on MRI scans by patches of increased signal in the white matter. Certain degenerative disorders of basal ganglia structures, associated with dementia, may have a characteristic appearance on MRI scans. Hunt- ington’s disease typically produces atrophy of the caudate nucleus; tha- lamic degeneration can interrupt the neural links to the cortex (Fig. 5.8-1).