CASE PRESENTATIONS

DR. IMRAN MAHFOOZ KHANMBBS, FCPS (MED)ASSISSTANT PROFESSOR,EAST MEDICAL WARD

CASE NO 1

A 25 year old male patient presented in Neurology OPD with

c/o weakness in his lower limbs, which was of gradual onset and progressive nature for the last 5 days. He initially had difficulty walking and at presentation was unable to support his own weight. He recalled severe pain and tingling sensations in his lower limbs before the weakness had started which persisted till now. He denied any H/o trauma, fall, loss of consciousness, current headache, fever or symptoms related to any GI or respiratory illness.

He was Non Diabetic, Non Hypertensive, with no significant family history.

Questioning on Past History just revealed an episode of cough, flu and fever about three weeks back. He did not seek medical treatment for it and got better on his own.

CASE HISTORY

When examined by the Resident Doctor, his vital signs

were as follows : Pulse = 78/min, regular, good volume BP = 110/ 70 mm Hg while supine, 80/60 mmHg while

standing up. Temp = 98 degrees F RR = 15/ minute

A detailed neurological examination confirmed weakness in his lower limbs. There was no sensory loss. Deep tendon reflexes in lower limbs could not be elicited. There was normal power in his upper limbs.

Remaining systemic examination, including chest examination was normal.

EXAMINATION

At one time during his ward admission, the on duty House Officer reported that the patient had become drowsy and non responsive. When checked his Oxygen saturation on Pulse Ox was 78 % (Normal > 85%). There was also an objective deterioration in his weakness.

The patient was put on Ventilatory support on immediate basis until further treatment could be offered.

…and then it got complicated

A gradually progressive, insidious lower limb motor weakness with no other symptoms of illness. Recent history of an upper respiratory tract illness, most likely viral.

Postural drop in blood pressure and reduced power in lower limbs with areflexia on examination.

Sudden deterioration in consciousness a few days later, with an inability to maintain oxygen saturation.

CASE SUMMARY

A subacute lower motor and autonomic dysfunction,

without an identifiable current off setting event.A feature of neuropathies, radiculopathies and spinal cord diseases. Sensory features may also be present separately or simultaneously.

Course complicated by weakening of respiratory effort which is also a motor dysfunction ( affecting the diaphragm)

Charecteristic feature of Guillain Barre Syndrome, a demyelinating polyradiculoneuropathy

ANALYSIS

Guillain Barre Syndrome

Provisional Diagnosis

GBS is basically demyelinating disorder of peripheral

nerves, that is immunologically mediated. Both B cell (humoral) and T cell (cell mediated)

components of the immune system may play a role in development of variable types of GBS.

The immune mechanisms are usually flared by an antecedent infection, most commonly Campylobacter jejuni ( a bacterium causing bloody diarrhea). Antibodies formed against such organisms may abnormally act on Schwann cells of peripheral nerves because of their resemblance to bacterial antigens. (molecular mimicry)

Pathophysiology

Molecular mimicry

Following tests are used to evaluate neuropathies :

1. Nerve Conduction studies.2. Electromyography.3. Lumbar Puncture / Spinal Tap for

Cerebrospinal Fluid Analysis.

Other investigations such as blood counts, CT scan, MRI may also be needed to rule out other causes of weakness

What next..??

PARAMETERS OF NCS :• Nerve conduction velocity• Nerve conduction latency• Nerve conduction

amplitude

Guillain Barre Syndrome is an immune mediated

demyelinating neuropathy causing progressive ascending paralysis and may lead to respiratory paralysis.

It is caused by an antecedent infection that has recovered at time of weakness, but immune response to the antigen can cause demyelination by molecular mimicry.

It is confirmed by NCS/ EMG and CSF analysis.

Learning Objectives

CASE NO 2

A 36 year old female patient presented to her physician with a c/o episodes of doubling of vision ( diplopia) for the last 2 months. She further explained that this occurred about two minutes into her reading and fully improved when she relaxed for a while. When asked she also described that her meals are becoming difficult to swallow even though she ensures that her food is well cooked and that she eats smaller bites every time.

While she was talking her physician also noted that she started fumbling after every two or three sentences and had to stop for a while. However once she resumed, her initial two sentences were perfectly normal.

Case History

The patient was also distressed over the fact

that she got tired very soon and despite taking her multivitamins with good diet, was unable to complete her daily tasks with the same efficiency.

Recently she became short of breath and fatigued while climbing stairs and had to sit down for 2 minutes to recuperate, after which she felt much better.

Her physician decided to do a complete physical examination.

Her vitals were recorded as follows :

Pulse = 78/minBP = 120/80 mmHgTemp = Afebrile RR = 18/min

Her cardiovascular, chest, abdominal and neurological examination were also normal. Visual acuity was 6/6.

The physician was able to demonstrate that her eye lids drooped when she was asked to look up and down repeatedly. At that time, she also complained of diplopia. It was further noted that ptosis and diplopia improved gradually with rest.

examination

An otherwise healthy and normally functioning

adult female with diplopia on reading, difficulty swallowing and easy fatigability that develops with exertion, all of which improve

to normal on resting.

Examination elicits ptosis on repeated eyelid movements.

CASE SUMMARY

Episodic and exertional muscular weakness with progressive fatiguibility, fully reversible on rest…

Hallmark of Neuromuscular Junction Disorders.

Important differentials include electrolyte disturbances, nutritional deficiencies and Anemias.

ANALYSIS

REVERSED ON REST

During rest, bound acetylcholine dissociates, exposing functional receptors.

NEUROMUSCULAR JUNCTION FATIGUEWith repetitive stimulation. Presynaptic Ach release normally decreases with each stimulation (presynaptic rundown). Patient becomes symptomatic when

at least 30 % receptor activity is lost. Severe fatigue can be debilitating (Myasthenic crisis)

POOR END PLATE POTENTIALDue to decreased stimulation, threshold for action potential not reached

REDUCED NUMBER OF ACETYLCHOLINE RECEPTORSDue to acetylcholine receptor autoantibodies (AntiAchR antibodies) against

the nicotinic Ach receptors on skeletal muscle end plate.

The underlying mechanism is an autoimmune

response to Acetylcholine receptors at the Neuromuscular Junction of skeletal muscle, usually starting with the extraocular muscles.

B cell mediated antibodies and T cell mediated immune mechanisms (centered in thymus) are both responsible.

Identifiable auto antibodies include AntiAchR antibodies or Anti Musk antibodies. Thymus may also be enlarged.

Myasthenia gravis – An autoimmune disease

Treated by improving the concentration of Ach at NMJ, by

administring inhibitors of enzyme acetylcholinesterase ,which breaks down Ach. (eg Pyridostigmine, Neostigmine)

Improvement in muscle fatigue with an anticholinesterase such as Edrophonium is diagnostic of Myasthenia Gravis or in severe cases, Myasthenic crisis. (Edrophonium Challenge Test)

Overdose with Anticholinesterase will lead to worsening of fatigue with further administration ( Cholinergic Crisis)

Anticholinesterases, Myasthenic Crisis & Cholinergic crisis

Progressive fatigability of muscles on exertion,

reversible on rest is hallmark of Neuromuscular Junction disease such as Myasthenia Gravis.

Myasthenia Gravis is an autoimmune disorder, improved with anticholinesterases.

Myasthenic crisis improves while cholinergic crisis worsens with Anticholinesterases.

Learning Objectives

CASE NO 3

A 16 year old male patient, with a visible spinal deformity

and a hunchback posture since birth but with a normal IQ level was brought to medical OPD, this time with active complaint of shortness of breath (dyspnea). This dyspnea, which previously only used to occur after walking a reasonable distance, now is present even when he has to walk to the washroom. For the last two weeks he has been getting severely short of breath even at rest, especially when he starts to cough.

He further elaborated that He also has a cough which is productive of yellowish green coloured sputum. He had fever about a week ago but it got better by using antipyretics.

Questioning about past history reveals that he has a history

of recurrent chest infections since childhood had to be hospitalized five times in last 2 years.

His infections recovered after a prolonged hospital stay and course of antibiotics, with persistence of shortness of breath.

These infections occur despite completion of routine vaccinations. Furthermore he does not have a family member with respiratory illness or TB (potential source of infection)

He is non diabetic, non hypertensive, with no H/o smoking, active or passive.

The attending physician decided to admit the patient and to carry out

a detailed physical examination. His vitals were recorded as follows :Pulse = 86/minBP = 100/70 mmHgTemp = 101 degrees FarhenheitRR = 38/min with a thoraco abdominal mode of respiration.

On detailed examination, deformity was noted in the dorsolumbar spine with a hunch in the thoracic spine. Patient had below average height, overall posture bent forward and rightward.

Chest symmetry and shape was altered, with increase in anteroposterior diameter, visible intercostal recessions, sternal prominence.

Chest examination revealed B/L expiratory crepitations (indicative of infective process).

When assessed on a pulse oximeter, it was

found that despite his best efforts, the patient was unable to maintain an oxygen saturation above 69%. He preferred leaning forward than lying down all the time and was unable to walk even a few steps.

He was put on continuous oxygen inhalation via mask. He was also administered antibiotics.

A male patient with vertebral deformity, having respiratory distress and History of

recurrent chest infections leading to repeated hospitalizations.

Case Summary

Common vertebral abnormalities include Kyphosis,

Scoliosis and Kyphoscoliosis.

Anatomical deformities affecting the spine or the chest can lead to poor respiratory effort. This is the cause of the frequent shortness of breath in such patients.

Poor respiratory effort is accompanied by impaired mucociliray clearance. This culminates in recurrent respiratory infections, which further worsen respiratory compromise.

Vertebral Deformities and Respiration

In kyphoscoliosis, lateral curvature, anteroposterior angulation, kyphosis, or several of these conditions are present.

In cases of disorders of the pleura and thoracic cage, the

total compliance by the respiratory system is reduced, and, hence, lung volumes are reduced, including total lung capacity, functional residual capacity and vital capacity.

As a result of atelectasis, gas distribution becomes nonuniform, resulting in ventilation-perfusion mismatch and hypoxemia.

The Cobb angle, an angle formed by 2 limbs of a convex prime curvature of the spine, is an indication of the severity of disease. An angle greater than 100° is usually associated with respiratory failure.

Effect of vertebral deformity on total lung capacity

Mucociliary movement moves the irritant substance towards upper respiratory tract , which is then expelled with a good coughing. This requires a strong respiratory effort.

Chest X Ray

MRI spine

Arterial Blood Gases ( check for serum pH, oxygen and CO2 partial pressures)

Sputum Culture and Antibiotic sensitivity testing.

Pulmonary Function Test

Tests

Kyphoscoliosis is an anatomical deformity of the spine in which lateral curvature, anteroposterior angulation, kyphosis, or several of these conditions are present.

The degree of curvature is measured by Cobb angle, if greater than 100, leads to respiratory compromise

Respiratory compromise caused by reduced lung compliance, total lung capacity, vital capacity and atelectasis, leading to hypoxemia.

Impaired mucociliary clearance is also present and is a source of recurrent chest infections.

Learning Objectives

Patients with such deformities require life long

assistance. Urgent admission of the patient when in respiratory

distress. Treat infections. Vaccination should be offered.

Investigate with Chest X Ray and Spinal MRI. Arterial Blood Gases when in acute distress. Pulmonary Function tests. Ventilatory Support if initial therapy fails. Wearing Orthopedic Supportive braces and

Surgical correction of defect.

Management and Support