Wednesday, May 17, 2023

Long Case - A Teenager With Lower Limb Weakness

Sharing one case we encountered in ward recently and is possible to encounter a similar scenario in the exams. 

An 18 year old male was returning from a feast after the Eid celebrations and found it difficult to get himself out of the car upon reaching home. He found it to occur suddenly. He was already feeling unwell (he could not describe how he was feeling unwell) since departing the feast. He had difficulty moving both his legs and he was also very lethargic. He had similar problems affecting his arms and he needed to be carried down from the car. He remained conscious throughout the indicent. 

Further history revealed no preceding or accompanying fever, no vomiting or diarrhoea, no bowel or bladder issues, no back pains. He had no headaches, no blurred vision, no dysphagia or speech abnormalities, no facial asymmetry. He also reported no palpitations or chest pains.

He did however report some numbness or tingling sensation affecting his extremities. 

In the past medical history section, he reported experiencing similar lower limb weakness occurring 4 months earlier in Jan 2023 for several hours. However at that time the weakness was not as bad as current presentation as he was still able to bear weight and walk although he needed assistance. He did not seek treatment at that time as he attributed it to being over tired after a game of soccer. His lower limb weakness gradually improved with leg massages and drinking "100-PLUS". Otherwise there was no other significant history with no previous hospital admissions or health issues. 

Family history was unremarkable as well with no similar occurrences affecting other members of his family. 

He had no significant drug history and he is not taking any medications or supplements. He did not consume herbal or traditional remedies either. 

Systemic review was also normal and he reported no significant weight loss or anorexia. 

Social history revealed he is studying at a local community college and is active is sports. He is a teetotaler and does not smoke. He is single and is not sexually active. He has not been involved in any illicit substances or recreational drugs. 

Physical examination showed him to be alert, calm with good hydration. There were no neurocutanoeus stigmata. He was afebrile with normal blood pressure.

However he was tachycardic. Manual heart rate was 120 beats per minute with regular rhythm and normal pulse volume. Capillary refill was normal. 

Neurological examination noted normal muscle bulk with no fasciculations noted. He had normal sensation in both upper and lower limbs as well. However he had proximal muscle weakness whereby hip flexion was only 3/5 bilaterally whereas shoulder abduction was also only 3/5 bilaterally. Ankle plantar and dorsiflexion was normal with power 5/5 and wrist dorsiflexion was also strong with power 5/5 bilaterally. 

There were fine tremors affecting both upper limbs. However muscle tone was normal for both upper and lower limbs. 

Reflexes were brisk in both upper and lower limbs but Babinski response was flexor (downgoing). There was no clonus elicited. 

There were no spinal cord abnormalities or tenderness found on examination of the spine.

Examination of the other systems revealed no heart murmurs or displaced apex beat, clear lung fields to auscultation and no goitre. Cranial nerves were normal and there was no proptosis and ophthalmoplegia.

A provisional diagnosis of periodic hypokalemic paralysis was made with a differential diagnosis of renal tubular acidosis and hyperthyroidism. 

12 lead ECG showed sinus tachycardia with a rate of 100 beats per minute with normal axis and no ST-T abnormalities. 

A bedside glucometer finger prick test revealed capillary blood sugar of 7.5 (random) which was normal. 

Blood tests were sent for blood gas analysis, kidney profile with electrolytes and also thyroid function testing. Urine tests were sent for any proteinuria or glycosuria. 

Blood gas results returned normal with no metabolic acidosis. 

His blood electrolytes showed hypokalemia at a level on 2.5 mmol/L. He received multiple intravenous potassium corrections on top of oral potassium replacements. 

Additional urine test for potassium excretion was ordered but unable to be tested due to lack of reagent (budget constraints). 

His hypokalemia proved difficult to correct and he required frequent and multiple intravenous potassium corrections on top of maintenance potassium in normal saline drip. 

Serum Magnesium was normal. 

Eventually, we discovered the actual diagnosis when the thyroid function test results returned after several days. His TSH was markedly suppressed at < 0.001 and his T4 was elevated at 58. 

He was commended on carbimazole and propranolol and soon after we found it easier to correct his hypokalemia. His tachycardia also improved and stabilised at 60-70 beats per minute. 

His lower limb and upper limb musle strength gradually improved and he was eventually able to self ambulate without assistance after 2 days of initiating anti thyroid therapy. 

Further history regarding autoimmune symptoms did not yield any positive history. Nevertheless, we decided to send thyroid autoantibodies. Ultrasound neck showed a slightly but diffusely enlarged thyroid gland with increased vascularity.

His final diagnosis was revised to Grave's Disease. 

The odd thing about this case was the absence of thyroid eye signs and a clinically palpable goitre. Perhaps we caught the disease in its early stages. He probably had hyperthyroidism for quite some time, perhaps preceding Jan 2023. As a result, his hypokalemia may already be there but he was compensating well. When he sweat a lot while playing soccer back in Jan 2023, his potassium levels probably plunged and he manifested as bilateral lower limb weakness.  His potassium levels were replaced partially after he consumed "100 PLUS" and thus resulting in gradual improvement in muscle weakness. Also important to take note is that Grave's disease is relatively uncommon among males and if the diagnosis is confirmed, overall prognosis wont be as good for male patients compared to female patients with Grave's disease. 

He was discharged well on Day 5 of anti thyroid treatment with oral potassium replacement. He was able to walk home unaided. There was no more hand tremors, his vitals have returned to normal levels and he is no longer tachycardic. 


CCE.

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Long Case - A Teenager With Lower Limb Weakness

Sharing one case we encountered in ward recently and is possible to encounter a similar scenario in the exams.  An 18 year old male was retu...