You are asked to evaluate a 36-year-old man who has been experiencing progressive limb weakness over the past 48 hours. The patient reports being an intravenous drug user and having a groin abscess drained recently. He also mentions having a stomach illness two weeks ago, but those symptoms have since resolved. During the physical examination, you observe flaccid weakness in all four limbs and absent reflexes in both lower limbs. The cranial nerves examination is unremarkable. What is the most likely diagnosis based on these findings?
MRCP2-3127
A 42-year-old Nigerian man presents with fatigue. He has been exhibiting strange behavior and psychotic symptoms for the past year and is currently being treated with risperidone. He was diagnosed with HIV-1 infection five years ago but has not been following up with treatment.
Upon physical examination, no abnormalities were found. His CD4 count is 20 × 106/l and HIV viral load is > 500,000 copies/ml. Antiretroviral therapy is initiated and the patient is discharged.
One month later, the patient returns with confusion. He is afebrile upon admission and disoriented in time and place but not in person. His CD4 count is now 50 × 106/l and HIV viral load is 503 copies/ml.
Further investigations reveal a hemoglobin level of 95 g/l, WCC of 4.8 × 109/l, neutrophils at 70%, lymphocytes at 20%, and platelets at 400 × 109/l. A CT scan of the brain shows multiple low-density lesions in the right hemisphere.
Cerebrospinal fluid analysis shows a white cell count of 150/ml, glucose level of 3.5 mmol/l, protein level of 0.6 mg/dl, and negative results for cryptococcal antigen, toxoplasmosis PCR, and India ink stain.
Four days later, the patient develops left-sided weakness. A magnetic resonance imaging scan with contrast shows diffuse enhancement of the lesions.
What is the most likely diagnosis?
MRCP2-3128
A 12-year-old boy is brought by his father to the clinic for evaluation of his neurological status. He has been experiencing a decline in academic performance for the past 4 months, and has been recently observed by his teacher to have outbursts of anger in the classroom.
His father is concerned that in the early morning his son experiences sudden contractions of his shoulder muscles and complains of blurry vision. This has been happening for the past 2 weeks. On the morning of his visit, he had a seizure followed by loss of consciousness. In his early childhood, he had a rash illness from which he recovered without any complications.
During the examination, the boy is lethargic and uncooperative. Cranial nerves appear normal. He experiences sudden contractions involving all four limbs. Tendon reflexes are brisk with bilateral Babinski’s sign. He has a wide-based gait and is unable to walk in a straight line. Blood pressure is noted at 110/75 mmHg, with pulse 90 bpm and regular. General physical review is unremarkable, as are routine blood tests and a chest X-ray.
What is the most likely diagnosis?
MRCP2-3129
A 25-year-old Japanese woman was brought to the Emergency Room on a stretcher as she was found lying on the floor of her apartment unable to move by her roommate. She had participated in a 5K race at a local park, the day before and had eaten a full chocolate cake before going to bed. She got up around 4 am to get a glass of water and noticed weakness in her limbs. She could hardly hold the glass and finally fell on the kitchen floor. Over the past few weeks, she has suffered from increasing heart palpitations and stress related to her upcoming exams.
Upon examination, she was of average build and anxious. She gave a clear account of the progression of her illness. Pulse was 110/min and irregularly irregular. Blood pressure was 130/90 mmHg. Cranial nerves were normal. Neck muscle power was 4/5. Shoulder girdle, truncal and pelvic girdle muscles 3/5. Tendon reflexes were decreased and plantar were absent. Sensation was intact.
What is the most probable diagnosis?
MRCP2-3130
A 35-year-old man presented to the emergency department with complaints of intense neck pain after shooting at a rifle range. He subsequently experienced vertigo, nausea, and vomiting. A few hours later, he was discovered collapsed at home and brought to the hospital by ambulance. On arrival, his Glasgow Coma Scale (GCS) score was 10 out of 15. What is the most probable reason for his symptoms?
MRCP2-3106
A 16-year-old girl presents after collapsing in a supermarket. She experienced hot and sweaty sensations, along with blurred vision before losing consciousness. Her mother reports that she was unresponsive and had limb twitching for twenty seconds before regaining consciousness. The patient has had three similar episodes in the past and her older brother has epilepsy. Although her ECG showed normal sinus rhythm, she felt nauseous and had urinary incontinence. What test is most likely to provide an accurate diagnosis?
MRCP2-3107
A 55-year-old construction worker visited his doctor complaining of weakness in his right shoulder and arm. He had difficulty lifting heavy objects above his head and had recently experienced reduced hand grip and numbness. These symptoms had gradually developed over the past two months after he fell from a plinth while working. The patient had a history of hypertension and mild asthma, smoked 20 cigarettes per day, and consumed 20 units of alcohol per week.
During the examination, the doctor observed winging of the right scapula and some wasting of the dorsal interossei and thenar eminence of the right hand. The patient had reduced tone in the right biceps and wrist, with absent biceps, triceps, and supinator jerks. Power testing revealed weakness in the right peri-scapular muscles, shoulder abduction, elbow flexion and extension, finger flexion and extension, and opposition of the thumb. Sensation was diminished over the thumb, right middle, ring, and little finger, extending over the medial and lateral aspect of the right forearm.
EMG and nerve conduction studies showed fibrillation potentials affecting small muscles of the right hand, with absent sensory nerve action potentials. Studies in the left arm were normal. Based on these findings, what is the most likely diagnosis?
MRCP2-3109
A 65-year old man presents to the clinic with a 2-week history of tingling in his hands and feet. He has also noticed that his legs feel weaker than usual. He has a history of high blood pressure and no other medical conditions. His vital signs are stable, but he appears sweaty and has a rapid heart rate. On examination, he has bilateral facial weakness and grade 4 weakness in his upper and lower limbs. His reflexes are present but require reinforcement. He has reduced sensation in his toes, ankles, and fingers. Which investigation is most likely to aid in the suspected diagnosis?
MRCP2-3110
A 65-year-old man presents with a 12-month history of forgetfulness and paroxysmal drowsiness. Upon examination by his GP, bilateral bradykinesia and rigidity in the upper limbs were found, and he was started on L-dopa. However, six weeks later, he developed formed visual hallucinations that persisted despite stopping the medication. The GP then prescribed a small dose of haloperidol (5 mg), but the patient experienced severe vomiting and drowsiness, which resolved upon discontinuing the medication. The patient has mild bradykinesias and rigidity in the upper limbs with rest tremor of the left arm, and his mini mental examination score is 20/30. The remainder of the examination is normal.
Investigations show normal results for CT brain and EEG, as well as for haemoglobin, white cell count, platelets, serum sodium, serum potassium, serum urea, serum creatinine, serum albumin, serum total bilirubin, serum aspartate aminotransferase, serum alkaline phosphatase, plasma glucose, free T4, free T3, and plasma TSH. However, the serum vitamin B12 level is low at 228 ng/L (160-760), and VDRL is negative.
What is the most likely diagnosis?
MRCP2-3111
A 44-year-old woman with a relapsing and remitting multiple sclerosis history presents for follow-up at the clinic. She has been stable for the last 6 months and is currently on oral fingolimod treatment. During the neurological examination, there is noticeable coordination impairment, particularly on the left side, but no other significant indications. What accurately describes the mechanism of action of fingolimod?