1 / 43

Common Diagnostic Procedures in Neurology

Common Diagnostic Procedures in Neurology. superKAT :) . Neuroimaging. Diagnostic imaging techniques Rapidly growing Increasing important in chronic and acute stages stroke Accuracy is essential . CT Scan – Computed Tomography. Provide “slice” images of brain and spinal cord

esben
Download Presentation

Common Diagnostic Procedures in Neurology

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Common Diagnostic Proceduresin Neurology superKAT :)

  2. Neuroimaging Diagnostic imaging techniques • Rapidly growing • Increasing important in chronic and acute stages stroke • Accuracy is essential

  3. CT Scan – Computed Tomography • Provide “slice” images of brain and spinal cord • Axial X-ray beams pass through the head • Amount of radiation is essentially harmless • Degree to which the tissue attenuate the X-ray beams are primarily important for differentiation

  4. Computed tomography • X-ray attenuation of the skull, CSF, cerebral gray and white matter, blood vessels • 30,000 beams of x-ray directed at several axial or coronal levels • Differing densities of bone and intracranial

  5. Indications • Infraction • Hemorrhages, AVM, aneurysm • Edematous tissue • Changes in cranial structures Useful for patients are neurologically/medicaaly unstable, uncooperative, clasutrahoibc with pacemakers

  6. CT angiography • Widely available • Less Specialized skill requirement • Less invasive intravenous administration

  7. Kinds of CT • Contrast enhanced CT (CECT) • Detect lesions that involve breakdown of blood brain barrier • Used to rule out brain tumors and abscesses • Intravenous contrast medium -based on iodine

  8. CT findings • Low attenuation – appear black • Air (darkest) • Fat • CSF and water • Medium attenuation – Gray • Edematous/infraction • Normal brain • Subacute hemorrhage • White • Hemorrhage • Intravenous contrast material • Bone or metal

  9. Appearance of ICH Hypertensive bleed • Occurs disruption of small arteries of thalamus and putamen • Acute or chronic hypertension • Located within the basal ganglia and pons

  10. Appearance of ICH • Hyperdense in all kinds of acute ICH • High hematocrit (90%) in hematoma after clotting and retraction • High density of protein component of Hgb • Mass effect of hematoma maybe present • Extended hypodense ring around an ICH may indicate perifocal edema (rare in the 1st 6 hours)

  11. Subarachnoid Hemorrhage • Spontaneous rupture of aneurysm of the basal cerebral arteries • Hemorrhage into subarachnoid space

  12. Appearance of SAF • Non contrast CT scan detect even small amounts of subarachnoid blood • Overall sensitivity is 92% to 98 within the first 24 hours after SAH • Gold standard is still lumbar puncture (drawing CSF from subarachnoid space)

  13. Appearance of SAF • Location does not necessarily predict origin except in combination with intracerebral hemorrhage • Can be misleading if ICH is large and aneurysm rupture is not considered

  14. Acute ischemic stroke • Result from the thrombo-embolic occlusion of intracranial arteries • Various patterns that can be seen in CT scan in early and late stages of the stroke

  15. Anterior cerebral artery • Isolated infract is rare • Local angiopathies such as vasculitis • More frequent found in carotid T-occlusions (ACA or MCA) • Following multiply cardioembolic events

  16. CT findings • Early • Clear visible hypodense area in cortical rim which may be missed occasionally • Late • Unusual to have difficulty in recognizing hypodensity of a lesion • Increase tissue contrast compared with normal brain tissue

  17. Middle cerebral artery (MCA) • Most common vessel in ischemic strokes = 75% of all • Symptoms vary between minor sensory or motor deficits • More patients scanned earlier to rule out hemorrhage and large infracts due to thrombolytic therapy

  18. Hyperdense MCA signs (HMCAS) • Clot is visible as hyperdense in MCA • Most evident in the horizontal part in the MCA • Appears as a vessel segment of higher density than other parts of same vessel, contralateral MCA and BA • Not an unequivocal sign of occlusion • Does not represent ischemic changes in parenchyma

  19. CT scan • Advantages Disadvantages • Easilly detecting: • Parenchymal bleed posterior circulation vascular disease • SAH, IVH bone related artifacts • Pressure effects limited views • Aneurysm suboptimal brain resolution • Readily available • Less expensive

  20. Complications • For contrast phase : caution among patients with renal problmes • Normal creatinine level

  21. Magnetic resonance imaging • Images displayed as maps of tissue signal intensity values • Spatial localization

  22. Provides thin clice images of the brain and spinal cord • Better resolution • Magnetic field aligns the protons of tissues and CSF in the orientation of the field • Radio frequency pulse causes the proton to resonate and chande their axis

  23. Indications • Hemorrhages • Ischemic/occlusive strokes (lacunes, brainstem and cerebellum) • Demyelinating disease • Tumors • Hypertensive encephalopathy • Vascular anomalies

  24. Advantages Disadvantages • Select any plane Claustraphobia • Does not need radiation bone imaging limited to display of marrow only • No bone artifacts cannot use with pacemakers no ferromagnetic implants • Brainstem lesions

  25. T1 images • Best for showing anatomy • CSF and bone appears black • Normal brain is gray • Flat and subacute hemmorhage appear (>48hours) white

  26. T2 images • Best for showing pathology • CSF and brain appear white • Normal brain=gray • Bone will appear black

  27. MR angiography • Prodcue images of intracranial and extracranial cerebral circulations • Adequate doe evaluation of large lesions • MR venography • Provides subtraction images of major venous sinuses • Useful in dural sinus thrombosis • Less sensitive that angiography

  28. Angiography • Provide high resolution images of the extra intra cranial cerebaral vasculature • Small cathther is threaded into extracranial vessels through the femoral artery

  29. Angiography – 4 vessel • Functional imaging test • Injection of contrast material • Flowing blood to produce signals • Occlusions, stenosis (narrowing), anuerysm • angitis

  30. Identifying the following • Occluded or stenotic vessel • Arterial dissection • Aneurysm • AVM • Vasculitic narrowing • Venous sinus thrombosis

  31. complications • Stroke • Most important complication • 1-2% • Results in emboli generated by catheter • Occurs more frequently in elderly with atherosclerosis dieses 2. Bleeding

  32. Transcranial Doppler (TCD) • Detects blood velocities (pattern of blood flow) • Temporal and Suboccipital window (VA, BA) • Temporal window (post cerebral, PCOM)

  33. ACA • MCA • BIFUR – siphon • PCA • BA • VERTebral artery • OPH • SIPHON – internal carotid hook up give branches to MCA and ACA

  34. sensitivity • Detect for occlusions • Stenosis

  35. EEG – Electroencephalography • Scalp electrodes • Examines spontaneous electrical activity of the brain • Tiny electrical potentials, measured as microvolts (uv), are recorded, amplified and displayed

  36. Preparations • Scalp clean • Precipitating activities • Induced drowsiness or sleep • Stroboscopic retinal stimulation (strobe lights)

  37. Indications • Epilepsy • Suspected seizure disorder • Toxic diseases – lead • Metabolic diseases – hypocalcemia, renal failures • Sleeping disorders – insomnia, sleep study • SSPE – subscleroting (?) pan encephalitis (widespread encephalitis), reactivation of measles virus, 9/10yrs until adolescence

  38. Lumbar puncture • To get CSF sample for diagnosis and treatment purposes, spinal needle – medium sized • Interspace: L4-L5 (infants), adults: L3-4 • Side lying position • Fetal like position • ASIS – anatomic landmark • Ensure bleeding parameters

  39. Preparations • Aseptic technique • Spinal needle • Test tubes • Manometer (pressure readings = opening and closing) • Sterile sheet • Sterile gloves • Cotton and Betadine • Band-aid, gauze

  40. Indications • Pressure measurements • Procure sample of CSF • Cellular, chemical and bacteriologic examination • Administer antibiotics, chemotherapeutic agents, spinal anesthetics • Detecting disease: • CNS infection (Meningitis) • Subarachnoid hemorrhage (SAH) • Neoplasms (no signs of impending herniation)

  41. CSF pressure measurement • CSF collection • CSF appearance – traumatic vs SAH • CSF analysis • Bacteriological (RBC, WBC, gm stain, AFB, india ink) • Biochemical (protein and glucose) • Special tests (Cell cytology – extension of cancer in the CNS, LJ culture – Lowenstein Jensen detect presence of CB, CALAS, oligoclonal bands – demyelinating process , Sabauraud’s culture)

  42. Normal Opening pressure = 80-180mm H20 RBC = 0-5cumm ideally none WBC = 0-5cumm all lymphocytes

  43. NPO and flat on bed for 4 hours • Complications: • Headache • Radicular pain • Vomiting

More Related