[Neuropathic pain following lesions of the infrapatellar branch of the femoral nerve : an important differential diagnosis in anterior knee pain]. / Neuropathische Schmerzen nach Läsion des R. infrapatellaris des N. femoralis : Wichtige Differenzialdiagnose chronischer Knieschmerzen.

We report on two patients with neuropathic knee pain following lesions of the infrapatellar branch of the femoral nerve due to knee joint replacement. In one patient, the neuropathic pain syndrome was complicated by the development of complex regional pain syndrome (CPRS II, causalgia). Patients exhibit a sharp, burning pain, often induced by exercise, and sensory impairment in the skin area supplied by the infrapatellar nerve. This nerve is a branch of the femoral nerve medial to the fascia lata and is responsible for the skin sensation of the anterior and medial part of the knee. Clinical features, anatomy, diagnostic methods and therapeutic options are reviewed.

[Hemisensory impairment in neuropathic pain following chronic radiculopathy]. / Hemisensorische Störungen bei neuropathischen Schmerzen im Rahmen chronischer Nervenwurzelreizsyndrome.

BACKGROUND: Modern pathophysiological concepts indicate that the central nervous system is important for chronification of pain in cases of neuropathic pain. Taking these concepts into consideration, what significance then do those hemisensory disorders have that appear sporadically in cases of chronic nerve root irritation syndrome? RESULTS: The typical clinical findings are illustrated by two case reports. In addition to persistent neuropathic pain, both patients experienced hemisensory impairment of the entire side of the body ipsilateral to the radicular symptoms. Perception of sensitivity to touch, pain, and temperature was decreased on the entire side of the body in contrast to the contralateral side. CONCLUSION: Hemisensory impairment in patients with chronic nerve root irritation syndromes can indicate a functional disorder in dealing with noxious impulses in the ventral posterior nucleus of the thalamus. They represent a clinical correlative to subcortical neuroplasticity, which could explain the resistance to therapy in severe chronic pain syndromes.