We describe a peculiar form of late onset paroxysmal cerebellar ataxia including clinical features similar to episodic ataxia type 2 (EA2) but unresponsive to acetazolamide. Four unrelated patients were clinically investigated. Neuropathological examination was performed in one patient and molecular analysis in all four. All 47 exons of CACNA1A were screened by a combination of single-strand conformer polymorphism and sequencing analysis in three patients. In addition, the length of the CAG repeat was determined in all four patients. The four patients were in their 60s at the onset of the disease, which was characterized by cerebellar ataxia attacks lasting from a few minutes to 1-2 h and occurring mainly in the morning. In the interictal period a nystagmus was present together with a slowly progressive cerebellar ataxia over the years. The neuropathological examination disclosed a dramatic loss of Purkinje cells mainly in the vermis. Moreover, certain cerebellar granular neurons had a strong cytoplasmic staining at immunopathological examination with an anti-tau protein serum. Search for truncating mutations or CAG repeat expansion in CACNA1A was negative. This late-onset paroxysmal cerebellar ataxia with neuropathological lesions restricted to Purkinje cells and with negative results both for truncating mutations and CAG expansion in the CACNA1A gene represents a new entity. Further studies are needed to delineate the underlying process.

An electrophysiological study was carried out on four patients with unilateral diaphragmatic paralysis. Whereas neurogenic involvement of the paralysed hemidiaphragm was roughly similar in all cases, neurogenic patterns could be detected in the normally moving controlateral hemidiaphragm in three cases, and the degree of involvement could be correlated with the respiratory state of the patients. EMG also showed that the neuropathic process affected the limb muscles. Thus unilateral diaphragmatic paralysis may be, at least in some cases, the localised expression of a more diffuse neuropathy, perhaps a peculiar form of neuralgic amyotrophy. Diaphragmatic paralysis has been attributed to multiple causes,"2 the most common being a tumour affecting the phrenic nerve. In some cases, however, the cause remains unknown and the paralysis is then called idiopathic.' [3][4][5] Bilateral diaphragmatic paralysis induces dyspnoea on exertion and supine position,2 whereas unilateral diaphragmatic paralysis may be asymptomatic and discovered only in routine chest x ray pictures. We carried out an electrophysiological study on four patients suffering from apparently unilateral idiopathic diaphragmatic paralysis. The paralysis was both isolated and complete on the chest x ray picture in all of the patients, although the respiratory complaints differed from case to case. Our aim was to determine whether the results of the electrophysiological tests could explain this disparity and investigate the mechanism of the paralysis. Patients and methods ELECTROPHYSIOLOGICAL METHODSThe tests were performed with MS6 (Medelec) or Viking (Nicolet) EMG apparatus. The patients were in a supine position. To record EMG a 7 cm long coaxial needle was inserted below the xiphoid appendix through the rectus abdominus and pushed along the posterior border of the stemum up to the sternal insertions of the right or left hemidiaphragm (RHD and LHD). The needle was left in place and conduction along the phrenic nerve was measured by stimulating the nerve with a surface electrode located at the lateral edge of the sternocleidomastoid. The latencies of the compound muscle action potential (CMAP) from the RHD and LHD after right and left phrenic nerve stimulation respectively, were measured and compared (normal range 6-8 ms). When the EMG showed motor unit potentials (MUPs) during deep inspiration in the paralysed HD but no CMAP after ipsilateral phrenic nerve stimulation, the controlateral phrenic nerve was stimulated to look for a possible crossed innervation. When we failed to record activity from the diaphragm with this method the coaxial needle was inserted under radioscopic control on the middle axillary line, between the seventh and eighth intercostal spaces and pushed up to the costal insertion of the diaphragm.6The CMAP after phrenic nerve stimulation was recorded as before. During these investigations no complications were observed, and coaxial needles gave information on MUPs and interference pattern that could not be obtained from surface ...

Inflammatory polyneuropathies are mainly known by their acute form, Guillain-Barré syndrome, but there are also chronic cases and all are considered as having an autoimmune mechanism. In each form, peripheral nerve biopsies show scattered macrophages in the endoneurium and in certain cases macrophages invade the Schwann cell cytoplasm and destroy the myelin sheath. In rarer cases there is a primary axonal degeneration. The authors studied two chronic cases, which both exhibited mixed primitive axonal and demyelinating lesions, with peculiar histiocytes in the endoneurium. These rounded cells were characteristically well marked by KP1 but showed well-developed rough endoplasmic reticulum cysternae at ultrastructural examination. Such plasmacytoid histiocytes have mainly been studied in subacute lymphadenopathies and have been only briefly illustrated in a few cases of peripheral neuropathies due to Lyme disease or HIV infection. The two cases reported here had no associated diseases and probably correspond to a peculiar subacute autoimmune reaction.