Basic Human Neuroanatomy
A Clinically Oriented Atlas 
Case 1 Answers

1.  Is there evidence of spinal cord involvement in this case and, if so, at what level?


2.  Is there evidence of dorsal or ventral root involvement or spinal nerve involvement in this case, and, if so, what is the level(s) of the involvement?  

No.  The patient’s motor, reflex, and sensory signs and symptoms do not follow a specific dermatomal or myotomal pattern.

3.  Is there evidence of plexus or peripheral nerve involvement in this case, and, if so, how would you differentiate between the two?  What evidence is there to support one or the other site of lesion in this case?  

Yes.  The patient’s signs and symptoms suggest involvement of two specific terminal peripheral nerves of the left lumbar plexus, the lateral femoral cutaneous nerve and the femoral nerve, while sparing other nerves of the plexus (e.g., the obturator, iliohypogastric, ilioinguinal, and genitofemoral nerves).  (see below)

4.  Indicate the level of the neurologic lesion in this case and the structures involved by the pathologic process.  

Diminished pinprick and touch perception over the left lateral thigh indicates involvement of the lateral femoral cutaneous nerve (L2, 3).  
Sensory impairment from the anterior and medial thigh and anteromedial leg suggests a lesion of the left femoral nerve (L2, 3, 4), including the territory of the anterior femoral cutaneous and the saphenous branches.
The weakness of the left hip flexors and knee extensors, and the asymmetric absence of the left knee jerk, suggest a lower motor neuron lesion involving the femoral nerve.
This pattern of involvement of these two peripheral nerves suggests that the lesion is above the inguinal ligament, near the origin of the nerves from the lumbar plexus.

5.  Where is the anatomical location of the pathologic process leading to this patient’s condition?  

The portion of the “lesion” causing neurological signs and symptoms is located in the posterior aspect of the lower abdominal cavity (i.e., the greater or false pelvis) near the psoas major and iliacus muscles.  

6.  In general, what type of pathological process do you think is involved in this case?

Retroperitoneal hematoma, which was a complication of heparin treatment of her deep vein thrombosis (DVT).

7.  What diagnostic procedure(s) would you undertake at this point?

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