Aims Clinical observation has led to the idea that there might be a distinc
tive form of selective sensory and autonomic neuropathy affecting patients
with Type 1 diabetic mellitus with severe symptomatic autonomic neuropathy
(Type 1-DAN) and this study was conducted to evaluate the presence of such
a neuropathy in Type 1-DAN.
Methods Nineteen Type 1 diabetic patients presenting for treatment of sever
e symptomatic autonomic neuropathy were examined (all had greater than or e
qual to 2 autonomic symptoms; age 39.3 +/- 10.2 years; duration of disease
25.6 +/- 10.5 years). For comparison, 19 Type 1 diabetic patients with neur
opathic foot ulcers (age 44.5 +/- 6.6 years; duration of disease 26.7 +/- 9
.2 years), 14 clinically uncomplicated Type 1 diabetic patients (age 39.9 /- 5.6 years; duration of disease 22.9 +/- 9.3 years) and 16 non-diabetic h
ealthy people as controls (age 39.3 +/- 10.7 years) were also examined.
Results The large fibre modalities (light touch and vibration perception) w
ere better preserved in the Type 1-DAN group than in the foot ulcer group.
Thus, light touch sensation was normal in 11 out of 19 Type 1-DAN patients
compared to only three out of 19 foot ulcer patients (P < 0.01), and vibrat
ion perception was 24.9 +/- 15.0 V and 40.5 +/- 7.9 V, respectively (P < 0.
002) with some of the Type 1-DAN patients in the normal range. In contrast,
the small fibre modalities, thermal perception and autonomic function, wer
e grossly abnormal in both groups (hot thermal perception 14.1 +/- 2.5 degr
ees C and 12.6 +/- 3.7 degrees C; cold thermal perception 13.8 +/- 2.7 degr
ees C and 10.9 +/- 4.7 degrees C; heart rate variation 2.9 +/- 1.5 beats/mi
n and 4.8 +/- 4.0 beats/min, respectively).
Conclusions There is indeed a subgroup of Type 1 diabetic neuropathy patien
ts who suffer from severe autonomic symptoms associated with a selective sm
all fibre sensory and autonomic loss with relatively preserved large fibre
sensory modalities.