Power Line to your Line to your Circuit Line to the station neighborhood house breaker living room. Outlet lamp Lamp with socket, Light bulb

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1 IMC 606 Neuroscience and Behavior Module Dr. Margaret Paroski Analysis of Sensory Lesions You walk into your living room and turn on the lamp. But no light comes on. What would you do? You would probably start by checking to see if the lamp was plugged in. Next, you would probably check the light bulb unscrew it and shake it to see if it was burned out, and try screwing a new light bulb into the socket. If those measures failed, you might try plugging the lamp into a different outlet. You would check to see if other lights or electric powered items in the house worked. Presumably, before entering the house, you noticed if all the street lights and lights in other homes were out. What were you doing throughout this process? You were examining a series of electrical connections, to see where the message was not getting through. You were localizing the lesion, starting with the most likely locations and then systematically checking a list of less likely alternatives. What were the choices? Let s trace circuit Power Line to your Line to your Circuit Line to the station neighborhood house breaker living room Outlet lamp Lamp with socket, Light bulb plugged into wiring, cord You may have ruled out some of the possibilities before you even started. For example, if other lights on the same circuit breaker were already on when you discovered the lamp wouldn t turn on, you wouldn t stop to consider a tripped circuit breaker as the problem, because you have evidence to the contrary. Other alternatives might require some thought. Did you notice if the streetlights or other houselights were on, or did you need to consciously think about it or even check. Some things you have to test like whether the light bulb is burned out. We go through a similar exercise in diagnosing neurologic lesions. We have a symptom numbness, weakness, clumsiness, etc. the equivalent of the lamp won t turn on. We have associated neural circuits including peripheral nerve pathways, spinal cord tracts and pathways in the brain. We have an analytical process where we look at associated problems ( lights out in other areas) to determine where the circuit must be disrupted to produce such a constellation of symptoms. The localization must be compatible with what doesn t work and what still works without disruption.

2 EXAMPLES CASE ONE VJ is a 38 year old female, who complains of a four month history of numbness in her right little finger and the adjacent side of her hand. She describes the numbness as a tingling feeling, which is painful at times. The pain and numbness are worse at night and with repetitive use of the upper extremities. VJ is employed as a receptionist. She has complained of aching in her neck and shoulders on and off for the past five years. She is trying to get into shape and has recently lost 40 lbs. On exam, she reports decreased appreciation of pinprick over the ulnar aspect of the hand extending to the wrist, the right little finger and the ulnar aspect of the ring finger. Strength is normal. CASE TWO DK is a 62 year old male who underwent a surgical procedure which entailed clamping the aorta above the renal arteries for 25 minutes. On awakening from anesthesia, he complained of low back pain and was unable to void. He said his legs felt numb and he complained of tingling in both lower extremities. He had no difficulty moving his arms, but he was unable to move his legs. On exam he had paralysis of his legs. He reported no appreciation of pinprick or temperature in the lower extremities extending to the bottom of his rib cage. Vibratory sense was intact throughout. Joint position was intact in the great toes and thumbs. CASE THREE Mr. T is a 50 year old male who complains of numbness in both arms. When he takes a bath, he has noticed that he cannot feel the water temperature with his arms or adjacent chest or back. He is a heavy smoker and has repeatedly burned his fingers on the right. On exam, he has impaired pinprick and temperature sense from his neck to just below his nipples on his chest. Pinprick and temperature sense are intact above and below those levels. Vibratory and joint position sense are intact throughout. His right elbow was noted to be enlarged and deformed.

3 SMALL GROUP CASES Case 1 Mrs. R. is a 46 year old woman who had a right mastectomy for breast cancer 18 months ago. Over the past month, she describes three episodes of tingling on the left side of her body. She says the tingling is sudden in onset and begins in her left hand and around the left side of her mouth. The tingling spreads up her arm then down her leg. The total duration of the episode is about one minute. Afterwards, she reports her left side feels funny for about 10 minutes, and then goes back to normal. On exam, pinprick, temperature sense, and vibratory sense are intact. With her eyes closed, she is able to identify when each hand is touched independently, but when her hands are touched simultaneously; she reports that only her right hand was touched. She has difficulty identifying objects wither left hand, and was unable to identify numbers traced in her left palm.

4 LESION ANALYSIS TEMPORAL PROFILE Occurrence episodic ongoing Onset sudden gradual Progression Severity of symptoms improving static worsening Distribution of deficit decreasing static increasing Sketch distribution of symptoms on figure provided.

5 SYMPTOMS hypesthesia/anesthesia paresthesia dysesthesia pain altered temperature perception other (describe ASSOCIATED SYMPTOMS ABNORMAL FINDINGS ON NEUROLOGICAL EXAM Distribution of deficit most consistent with pathology involving a single peripheral nerve (name) multiple peripheral nerves the brachial or lumbosacral plexus nerve root (specified) the spinal cord (specify location) the brainstem (specify location) the thalamus the parietal lobe From the information available to you regarding temporal profile, neuroanatomical localization, associated symptoms and past medical history, what differential diagnosis would you propose?

6 SMALL GROUP CASES Case 2 Ms. L. is a 22 year old female who presents with a 3-week history of numbness in all her extremities. She complains that her hands feel thick and sometimes it feels like something is squeezing her arms and legs. She works as a waitress, and has had difficulty handling coins and bills when making change for customers. She has dropped food while serving customers twice in the past week. On exam, pinprick and temperature sense are intact. She says light touch on her arms, legs and torso feels different than light touch on her face, but she is unable to describe exactly how it is different. With her eyes closed, she cannot identify whether her fingers or toes have been moved up or down. Vibratory sense is decreased in the sternum and all extremities and is intact on the face. She has difficulty with fine hand movements. She is unable to tie a bow or thread a needle. When asked to rapidly pick up and stack coins placed on the exam table, her movements are somewhat awkward and imprecise. When asked to touch her fingertip to her nose with her eyes closed, she has difficulty finding her nose. When standing with her eyes closed, she sways, and requires support from the examiner to prevent her from falling.

7 LESION ANALYSIS TEMPORAL PROFILE Occurrence episodic ongoing Onset sudden gradual Progression Severity of symptoms improving static worsening Distribution of deficit decreasing static increasing Sketch distribution of symptoms on figure provided.

8 SYMPTOMS hypesthesia/anesthesia paresthesia dysesthesia pain altered temperature perception other (describe ASSOCIATED SYMPTOMS ABNORMAL FINDINGS ON NEUROLOGICAL EXAM Distribution of deficit most consistent with pathology involving a single peripheral nerve (name) multiple peripheral nerves the brachial or lumbosacral plexus nerve root (specified) the spinal cord (specify location) the brainstem (specify location) the thalamus the parietal lobe From the information available to you regarding temporal profile, neuroanatomical localization, associated symptoms and past medical history, what differential diagnosis would you propose?

9 SMALL GROUP CASES Case 3 Mr. J. is a 70 year old man with a long history of high blood pressure. While mowing the lawn one week ago, he experienced sudden onset of numbness on his entire right side including his face. He said his right side is not weak, but he has had difficulty walking. He feels his right-sided numbness has improved somewhat over the past week, but he is beginning to experience unprovoked pain over his right side. On exam, he reported marked reduction in perception of pinprick, temperature and vibration on the right side. He could not identify whether his fingers and toes were moved up or down on the right side with his eyes closed.

10 LESION ANALYSIS TEMPORAL PROFILE Occurrence episodic ongoing Onset sudden gradual Progression Severity of symptoms improving static worsening Distribution of deficit decreasing static increasing Sketch distribution of symptoms on figure provided.

11 SYMPTOMS hypesthesia/anesthesia paresthesia dysesthesia pain altered temperature perception other (describe ASSOCIATED SYMPTOMS ABNORMAL FINDINGS ON NEUROLOGICAL EXAM Distribution of deficit most consistent with pathology involving a single peripheral nerve (name) multiple peripheral nerves the brachial or lumbosacral plexus nerve root (specified) the spinal cord (specify location) the brainstem (specify location) the thalamus the parietal lobe From the information available to you regarding temporal profile, neuroanatomical localization, associated symptoms and past medical history, what differential diagnosis would you propose?

12 SMALL GROUP CASES Case 4 Mr. X. is a 33 year old construction worker who reports he experienced sudden onset of back pain while unloading a truck two weeks ago. He says the pain radiates down the back of his left leg into his foot. He complains of tingling along the lateral aspect of his left calf extending to the dorsum of his left foot and his big toe. He said the pain and tingling increase when he coughs or strains to move his bowels. He denies any weakness in his leg or any problems controlling his bowel or bladder. On exam, he reports decreased perception of pin over the left lateral calf and the medial aspect of the dorsum of the foot including his medial three toes.

13 LESION ANALYSIS TEMPORAL PROFILE Occurrence episodic ongoing Onset sudden gradual Progression Severity of symptoms improving static worsening Distribution of deficit decreasing static increasing Sketch distribution of symptoms on figure provided.

14 SYMPTOMS hypesthesia/anesthesia paresthesia dysesthesia pain altered temperature perception other (describe ASSOCIATED SYMPTOMS ABNORMAL FINDINGS ON NEUROLOGICAL EXAM Distribution of deficit most consistent with pathology involving a single peripheral nerve (name) multiple peripheral nerves the brachial or lumbosacral plexus nerve root (specified) the spinal cord (specify location) the brainstem (specify location) the thalamus the parietal lobe From the information available to you regarding temporal profile, neuroanatomical localization, associated symptoms and past medical history, what differential diagnosis would you propose?

15 SMALL GROUP CASES Case 5 LB is a 32 year old male with a history of Hodgkin s disease. Approximately 6 weeks ago, he began experiencing neck pain. The pain radiated down his left arm to his thumb. He complained of numbness on his right side and noted that in the shower he could not determine the water temperature with his right lower arm or right leg. He could feel the water temperature on his right upper arm and face. He had been dragging his left leg and complained of dropping things with his left hand. On exam, he had decreased appreciation of pinprick and temperature on the right side involving his leg, trunk, and ulnar aspect of his right arm. He had impaired vibratory sense in his left lower extremity and the fingers of his left hand. He had impaired joint position in the left leg and fingers of the left hand and decreased light touch sensation in his leg, trunk and hand on the left. Weakness was noted in the left leg and left hand.

16 LESION ANALYSIS TEMPORAL PROFILE Occurrence episodic ongoing Onset sudden gradual Progression Severity of symptoms improving static worsening Distribution of deficit decreasing static increasing Sketch distribution of symptoms on figure provided.

17 SYMPTOMS hypesthesia/anesthesia paresthesia dysesthesia pain altered temperature perception other (describe ASSOCIATED SYMPTOMS ABNORMAL FINDINGS ON NEUROLOGICAL EXAM Distribution of deficit most consistent with pathology involving a single peripheral nerve (name) multiple peripheral nerves the brachial or lumbosacral plexus nerve root (specified) the spinal cord (specify location) the brainstem (specify location) the thalamus the parietal lobe From the information available to you regarding temporal profile, neuroanatomical localization, associated symptoms and past medical history, what differential diagnosis would you propose?