The Neurologic Screening

MOHAMMAD R.GHEINITEHRAN UNIVERSITY OF MEDICAL SCIENCE

SINA HOSPITAL

Neuro Exam

A comprehensive neurologic screening exam can be accomplished within minutes if performed in an organized and systematic fashion.

The neurological examination is not applied in its entirety to asymptomatic, otherwise healthy people as the yield (i.e. likelihood of identifying occult disease) would be quite low.

A full mental status exam is not necessarily warranted in the patient who is awake, oriented, and conversant,

The Neuro Exam: Physical

Vital SignsNeck: Bruits, RigidityHeart: MurmurSkin / Scalp: Lesions / Tenderness

Neurological Screening

Determine the blood pressure in both arms. Have patient raise eyebrows, wrinkle forehead,

close their eyes and smile (CN 7). Check sensation to touch on face; Feel temporal

and masseter muscles when jaw clenched (CN 5). Assess extra occular movements (cranial nerves 3,

4, & 6). Check visual fields and acuity (CN 2) if

appropriate. Using ophthalmoscope, check pupillary response

to light (direct and indirect). Look for red reflex. Examine external structures of the eye.

Perform fundoscopy.

Neurological Screening

Palpate the spine. Listen over the carotids.Assess for Babinski. Have patient stand and then walk. Observe

gait. Check for Romberg's Sign.

Pearls in diagnosing papilledema

Blurring of the lateral margin of the optic disc

Loss of blood vessels as they cross the edematous disc

Distended veinsLoss of venous pulsations

Plantar Response

Stroke the lateral aspect of the sole of each foot with the end of a reflex hammer or key. Note movement of the toes, normally flexion

Extension of the big toe with fanning of the other toes is abnormal. This is referred to as a positive Babinski.

Pitfalls In The Neurologic Exam

Not getting a complete history utilizing family or observers

Not performing a systematic examJumping to conclusions before

gathering all the dataMisinterpreting old lesions for new Misinterpreting limitations from pain

as neurologic deficits

Risk factors and their management for stroke

prevention

Learn neurology “stroke by stroke.” C.M.Fisher

Six risk factors

HypertensionMyocardial infarctionAtrial fibrillationDiabetes mellitusBlood lipidsAsymptomatic carotid artery stenosis

Reletive Risk (RR)= a/a+b/c/c+d=a(c+d)/c(a+b)Odds ratio (OR)=a/b/c/d=ad/bc

StrokeStroke

++StrokeStroke

--

Risk Factor Risk Factor ++

aa b a+ba+b

Risk Factor -Risk Factor - cc dd c+dc+d

a+ca+c b+db+d

Risk factors

The proportion of ischemic stroke in the population that can be attributed to a particular risk factor is called the attributable risk (AR) .

This equation shows the influence of both relative risk and prevalence of the risk factor on the value of AR.

Prevention

Absolute risk reductionRelative risk reductionNumber need to treatLife expectencyProcedure riskSubgroup analysis

Risk factors

Despite the advent of treatment of selected patients with acute ischemic stroke , the best approach to reducing the burden of stroke remains prevention.

Stroke is well suited for prevention since it has a high prevalence, high burden of illness and economic cost, well-defined modifiable risk factors, and effective prevention measures

Epidemiological data suggest a substantial leveling off of prior declines in stroke-related mortality and a possible increase in stroke incidence

Well-documented modifiable risk factors were considered as those with clear, supportive epidemiological evidence in addition to evidence of risk reduction with modification as documented by randomized trials.

Hypertension

The incidence of stroke increases in proportion to both systolic and diastolic blood pressures.

“direct and continuous.” A relative risk of stroke of approximately 4 when hypertension is

defined as systolic blood pressure>or=to160 mm Hg and/or diastolic blood pressure >or=to95 mm Hg.

Up to 50% of strokes may be attributable to hypertension. BP measurement should be an essential component of regular

health care visits; BP should be lowered to normal (140/85 mmHg) values by means of life-style and/or pharmacological treatment (Level I)

Isolated systolic hypertension is an important risk factor for stroke in the elderly (systolic blood pressure >160 mm Hg and diastolic blood pressure <90 mm Hg)

The Systolic Hypertension in the Elderly Program (SHEP) trial demonstrated a 36% reduction in the incidence of total stroke with antihypertensive treatment (SHEP Cooperative Research Group. Prevention of stroke by antihypertensive drug treatment in older persons with isolated systolic hypertension JAMA. 1991;265)

Diabetes, Hyperinsulinemia, and Insulin Resistance

A constellation of metabolic risk factors has also been identified in some type 2 diabetics. The main characteristics are hyperinsulinemia and insulin resistance.

These result in the secondary features of the syndrome, including hyperglycemia, increased very-low-density lipoprotein cholesterol,decreased HDL cholesterol, and hypertension.

Increased relative risk of stroke in diabetics ranging from 1.8- to nearly 6-fold.

Overall, persons with glucose intolerance have double the risk of brain infarction compared with nondiabetics

Diabetes, Hyperinsulinemia, and Insulin Resistance

Tight control of hypertension in diabetics significantly reduces stroke incidence (44% relative risk reduction compared with more liberal control)

Control of hypertension in diabetics and treatment of high-risk diabetic patients with the ACE inhibitor prevent stroke.( Heart Outcomes Prevention Evaluation Study . Effects of ramipril on cardiovascular and microvascular outcomes in people with diabetes mellitus: results of the HOPE study Lancet. 2000;355)

Glycemic control is recommended to reduce microvascular complications

Hyperlipidemia

For ischemic stroke, some studies have found a weak association between serum cholesterol and an increasing risk of cerebral infarction (The adjusted risk ratio was 1.8 for those with serum cholesterol 240 to 279 mg/dL and 2.6 for those with cholesterol levels >280 mg/dL.)

There are reports of an inverse association between total cholesterol and cerebral hemorrhage, with a greater mortality from hemorrhagic stroke among those with serum cholesterol levels <160mg/dL.

Hyperlipidemia

In 1998, the Food and Drug Administration (FDA) approved simvastatin to reduce the risk of first stroke or TIA in people with high total cholesterol and coronary heart disease.

Meta-analysis of 90 000 randomized patients shows that statins significantly reduced all strokes without increasing brain hemorrhage and this effect is mainly driven by the extent of between-group LDL-C reduction. (Stroke. 2004;35:2902-2909.)

Reductions of LDL with statins can modestly retard the progression of asymptomatic carotid atherosclerosis

Statins may also act through mechanisms unrelated to their lipid-lowering properties, such as improved endothelial function, plaque stabilization, and antithrombotic, anti-inflammatory, and neuroprotective properties

Inflammatory Processes

Atherosclerosis is now believed to be a disease of chronic inflammation.

Destabilization of the atheromatous plaque is a forerunner of ischemic stroke and myocardial infarction.

Typically, the at-risk or vulnerable asymptomatic atherosclerotic coronary artery plaque is not associated with high-grade stenosis.Instead, it is characterized by a large lipid-rich core, thin fibrous cap, reduced collagen content, and an active chronic inflammatory component.

Chlamydia may participate in plaque progression and destabilization as opposed to initiation of atherosclerosis, which may be why there appears to be a relationship between serum antibody titers to C pneumoniae and stroke

C-reactive protein

There is a significant and positive association between plasma CRP levels and the risk of vascular events, including stroke.

The efficacy of common preventive agents such as aspirin and HMG-CoA reductase inhibitors may be related, at least in part, to their anti-inflammatory effects.

In the Physicians’ Health Study, aspirin significantly reduced the risk of vascular events only among men in the highest quartile of CRP levels, although the direct effect of aspirin on CRP is unclear.

Carotid Artery Stenosias

Patients were classified as symptomatic if they had a carotid distribution TIA or nondisabling stroke in the preceding 6 months

In asymptomatic patients with stenosis < 80% and Aspirin treatment only, there is 1% per year risk of stroke

The risk of stroke in symptomatic patients treated with antiplatelet therapy alone is thought to be 26% in 2 years.

Population-based studies indicate that the prevalence of carotid stenosis is 0.5% by the sixth decade of life, but increases to 10% by age 80 years

Extracranial internal carotid artery stenosis accounts for 15 to 20% of ischemic strokes

symptomatic carotid stenosis

A symptomatic carotid stenosis of 70 to 99 percent is a proven indication for CEA

The surgical risk should not exceed 6 %The greatest benefit from CEA is likely to be

achieved if surgery takes place within two weeks of a nondisabling stroke or TIA.

It is recommended that the patient have at least a 5-year life expectancy.

CE should not be considered for symptomatic patients with less than 50% stenosis

Asymptomatic carotid disease

If CEA is considered for asymptomatic patients, the potential benefit is most likely to be realized in:

medically stable men with stenoses of 60 to 99 (especially 80 to 99)percent

have a life expectancy of at least five years and treated by surgeons with a demonstrated

perioperative complication rate that is less than 3 percent

The evidence supporting CEA in asymptomatic women is less compelling.