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Showing posts with the label Neuropsychiatry

Functional Magnetic Resonance Imaging (fMRI)

Functional Magnetic Resonance Imaging (fMRI) Introduction Structural imaging reveals the static physical characteristics of the brain. It makes it useful in diagnosing disease. Functional imaging reveals dynamic changes in brain physiology that might correlate with cognitive functioning, for example. Neural activity consumes oxygen from the blood. This triggers an increase in blood flow to that region and a change for deoxyhemoglobin in that region. As the brain is always physiologically active, functional imaging needs to measure relative changes in physiological activity. The most basic experimental design in functional imaging research is to subtract the activity in each part of the brain whilst doing one task away from the activity in each part of the brain whilst doing a slightly unfamiliar task.  We call this cognitive subtraction . Other methods, including parametric and factorial designs, can minimize many of the problems associated with cognitive subtraction. There is no foolp

Positron Emission Tomography (PET)

Positron Emission Tomography (PET) Positron Emission Tomography is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, regional chemical composition, and absorption. They use different tracers for different imaging, depending on the target process within the body. We inject a radiopharmaceutical—a radioisotope attached to a drug—into the body as a tracer. Gamma cameras emit and detect Gamma rays to form a three-dimensional image, similar to that of an X-ray image. Positron-emission tomography scanners can incorporate a computerized tomography scanner, and we call them positron-emission tomography-computerized tomography scanners. One disadvantage of a positron-emission tomography scanner is its high initial cost and ongoing operating costs. Applications Positron-emission tomography can give information about: Metabolic changes Regional c


Pneumoencephalography Pneumoencephalography (sometimes abbreviated PEG, and some knew it as an "air study") was a common medical procedure in which they would drain most of the cerebrospinal fluid from around the brain with a lumbar puncture and replaced it with air, oxygen, or helium to allow the structure of the brain to show up more clearly on an X-ray image.  They derived it from ventriculography , an earlier and more primitive method where they would inject the air through holes drilled in the skull.

Tourette Syndrome

Tourette Syndrome Clinical features >> Diagnostic and Statistical Manual of Mental Disorders, 5th Edition. Multiple vocal and motor tics  Starting before the age of 18 and  Persisting for a duration of at least one year We have excluded other causes of tics. LOSE Learning difficulties  Overactivity  Social problems  Emotional disturbances Maudsley Prescribing Guidelines (13th Edition)  They recommend  alpha-2 agonists  such as Clonidine or Guanfacine as the first-line pharmacological treatment for Tics and Tourette Syndrome  American Family Physicians and Canadian Guidelines Antipsychotics possess a variety of serious adverse effects (Pringsheim et al., 2012) and even though the evidence base for them is strong, we use them in cases not responding to alpha-2 agonists. References Taylor, D. (2018). The Maudsley Prescribing Guidelines. The Maudsley Prescribing Guidelines.  Kenney, C., Kuo, S.-H., & Jimenez-Shahed, J. (2008). Tourette’s syndro

Cognitive Deficits in Multiple Sclerosis

Impairment of learning, abstraction, memory, and problem-solving occur in patients with multiple sclerosis. These impairments are present in 40% of patients with multiple sclerosis in the community. Sometimes, it is an early manifestation.  Mostly the impairments are seen later in the course. The impairments are mild and progress slowly.  Well-practiced verbal skills are often preserved.  Cognitive impairment correlates with total lesion load and degree of callosal atrophy on brain imaging.  LAMP L earning A bstraction M emory P roblem-solving

Clinical features of complex partial sezires, Mnemonic

"P ardon DJ H ell, you are P roducing GAS that is AFFE Cting A ll the F earful TEDS, C o ST ing them M aDness"  P erceptual: D istorted perceptions, D eja Vu J amais Vu H allucinations  P sychomotor G rimacing and other body movements  A utomatisms S tereotyped behaviors A ffective F ear and anxiety E uphoric or ecstatic states A utonomic and visceral  F lushing T achycrdia  E pigastric aura D izziness Other bodily S ensations C ognitive S peech disturbances T hought disturbances M emory disturbances D epersonalization, d erealization 

Better imaging study for the assement of change in behavior

Patient has change in behavior. Would it be preferable to use CT with contrast or without contrast for assessment ?LikeShow more reactions Comments Sarmad Mushtaq Ct withcontrast  Immo Mani With contrast Valeed Ahmed Yess with contrast,,, inflammation and tumors etc can create change in behavior that can be better viewed by contrast enhanced CT, contrast agents can not enter the BB barrier except in arease of inflamation where the barrier is damages ir tumor where it is not formed,,,so the contrast enters there very well, making the area distinct due to more absroption of radiation

Mechanism of Dementia in Downs Syndrome

Which of the following is responsible for dementia seen in adults with Down’s syndrome? A. Loss of genetic material in chromosome 21 B. Extra genetic material in chromosome 21 C. Genetic material lost from chromosome 14 D. Loss of genetic material corresponding to presenilin -1 E. Loss of genetic material corresponding to Apoe4 Ok extra genetic material is the correct answer. The gene that codes for b amyloid is located on chromosome 21. Since down syndrome is due to trisomy 21 so there is increased amount of genetic material that production of its product proteins. Product protein of the APP gene located on chromosome 21 is beta amyloid that is central to the aetiology of alzheimers

Corticobasal Degeneration

Corticobasal Degeneration Corticobasal ganglionic degeneration present with asymmetric basal ganglia (akinesia, rigidity, dystonia) and cerebral cortical (apraxia, cortical sensory loss, alien limb) manifestations. We see the alien limb with parietal lobe, medial frontal lobe, and corpus callosum pathology. Dementia is a variable but may be the presenting symptom.  Oculomotor involvement like that in progressive supranuclear palsy may occur. But the major difference between PSP and corticobasal degeneration is that the latter is with limb coordination problems, and the former is with balance and walking problems.  Prognosis Survival ranges from 2.5 to 12 years, with a median of about 8 years.  Neuropathology Corticobasal degeneration pathology shows abundant ballooned, achromatic neurons, and focal cortical atrophy predominating in medial frontal and parietal lobes, plus degeneration of the substantia nigra. We also see astrocytic plaques in the cortex. corticobasal degeneration: neuro

Single-photon Emission Tomography SPET

Single-photon Emission Tomography SPET Principle uses single-photon (gamma-ray) emitting isotopes given IV or inhaled the resolution is lower than PET Uses SPET can give information about: regional cerebral blood flow ligand binding Clinical uses include: Alzheimer’s disease When the symptomatology (e.g. hallucinations, epilepsy) occurs when the patient is not near a scanner; we can give a suitable ligand at the material time and the patient scanned afterward Schizophrenia reduced rCBF in frontal regions—‘hypofrontality’ Affective disorders as that in schizophrenia, with reversal after antidepressant therapy Alzheimer’s disease decreased rCBF in posterior parietal and temporal regions Xenon inhalation Shows the failure of activation of frontal lobes in schizophrenics performing the Wisconsin Card Sorting Test