|Year : 1992 | Volume
| Issue : 3 | Page : 164-168
Digital blood circulation in paucibacillary leprosy
Sanjay Ghosh, A Biswas
Source of Support: None, Conflict of Interest: None
Digital vascular flow in paucibacillary leprosy was assessed photoplethysmography (PPG). In PPG, infra-red light emitting diode and an adjacent photosensor detect the blood flow in cutaneous capillaries, as represented graphically on a strip-chart. In 29 (6F, 23 M) untreated paucibacillary leprosy patients (7TT, 16 BT and 6 purely neural type) having ailment on limb/limbs, suffering for 5 months to 12 years, PPG recording were done by applying the device to the distal phalanges of all the digits of four limbs serially with Velcro-strap at an ambient temperature of 28 °C - 30 °C and humidity of 60-70 percent. Diminished digital vascular flow of the affected limb/limbs was seen in long-standing cases suffering for > 2 years irrespective of the type, site, morphology or phase (reactional) of the disease. This may be mostly due to specific vascular changes rather than reactional or functional changes. Specific vascular changes are terminal arteritis, vasculitis of vasa nervorum or truncular arteritis, i.e.. tuberculoid lesions of the major arteries. Two patients, suffering for 1.5 years, paradoxically showed increased digital blood flow which is probably due to reactive hyperaemia or paralytic vasodilatation as a result of autosympathectomy.
Keywords: Leprosy, Vascular changes, Photoplethysmography (PPG)
|How to cite this article:|
Ghosh S, Biswas A. Digital blood circulation in paucibacillary leprosy. Indian J Dermatol Venereol Leprol 1992;58:164-8
|How to cite this URL:|
Ghosh S, Biswas A. Digital blood circulation in paucibacillary leprosy. Indian J Dermatol Venereol Leprol [serial online] 1992 [cited 2020 Sep 19];58:164-8. Available from: http://www.ijdvl.com/text.asp?1992/58/3/164/3786
| Introduction|| |
Vascular changes form the basis of a large variety of symptoms and signs seen in leprosy. Chatterjee,  from the result of his clinical experiments, was the first to propose that in many cases of Hanseniasis the neurological deficit was not due to Wallerian degeneration More Details, but was due to ischaemia of nerves. His prophetic statement was later confirmed by Carayon's  major investigational research. He employed neurographies, selective arteriographies and lymphographies to study nerve circulatory disorder in leprosy.
In Hansen's disease, biopsy and autopsy studies also revealed vascular pathological changes. Fite  found tuberculoid lesions causing obstruction in major arteries of the limbs in leprosy. Desikan and Job  by post-mortem studies showed atheromatous changes within aorta among leprosy patients. Still, the dynamic visualisation of blood or lymphatic supply rather than biopsy or autopsy studies is more valuable for providing information on vascular pathophysiology of leprous lesions. Keeping this idea in mind, we desired to carry out further works in this field.
Digital vessels are particularly prone to be involved in any vascular pathological process. A non-invasive, highly sensitive technique called photoplethysmography (PPG) was therefore utilised to assess the digital micro-circulation in paucibacillary leprosy.
| Materials and Methods|| |
In total, 29 untreated patients (6F, 23M), aged between 13 to 70 years, suffering from paucibacillary leprosy with involvement of limb/limbs were selected for the study. Duration of their illness ranged from 6 months to 15 years. The number of patients in different types of paucibacillary leprosy i.e. tuberculoid(TT), borderline tuberculoid(BT) and purely neural (with features of paucibacillary leprosy) were respectively 7, 16 and 6. Among them, 8 patients showed features of reactional phase and 9 patients exhibited trophic ulcer. All these patients were diagnosed mainly by cardinal features of leprosy. Histamine flare test, sweat function test, histopathological examination of skin or nerves, slit-skin smear for acid fast bacilli, nerve conduction test were also used in certain cases to confirm the diagnosis of the disease and its type.
Photoplethysmography(PPG) is the most sensitive of commonly available types of plethysmography. It is a technique that measures the optical density of blood in the cutaneous capillaries. The instrument (Vaslab-IV, Vascular recorder, designed by Messers Kodys, Madras, India) has a probe in which a light emitting diode and a photosensor-are mounted side-by-side. The diode emits infra-red light which is absorbed by the haemoglobin of blood. The scattered reflected light is absorbed back by the photosensor and is instantly measured. This is represented graphically on a strip-chart. 
The method consisted of applying the PPG probe to the distal phalanx with the supplied velcro-strap to block out ambient light. With the patient in supine position, the photocell was first attached to the right thumb pad area. The size (gain) control was so adjusted that the stylus deflection for the pulse wave was approximately 2025 mm. Graph of 5-7 pulse waves were recorded. This procedure was repeated for nine remaining upper extremity digits without changing the size (gain) control. The capillary flow of lower extremity digits were similarly graphed. Our study was conducted at ambient temperature of 28 ° C - -sub 30 ° C and humidity 60-70 percent.
| Results|| |
Representative PPG graphs of digital micro-circulation of certain patients have been depicted in the [Figure - 1][Figure - 2][Figure - 3][Figure - 4][Figure - 5][Figure - 6].
Diminished digital blood flow in affected limb/limbs was seen in 19 (65.52%) patients. All these patients were suffering from the disease for 2 years or more. In 2 (6.89%) patients, suffering for 1.5 years, digital flow in the affected limb was increased as compared to normal. In 8 (27.59%) patients, having the ailments for less than 1.5 years, digital flow was normal. Alteration of digital vascular flow in the patients had no bearing upon the type, site, morphology or phase (reactional) of the lesions. Beyond 2 years of involvement, no correlation was found between the duration of the disease and number of digits showing impaired vascular flow (correlation co-efficient r.y_+1.62).
| Comments|| |
Vascular pathology in leprosy includes specific, reactional or functional changes. Among specific changes, terminal arteritis, vasculitis of vasa nervorum and truncular arteritis are seen. In tuberculoid leprosy, arteritis of terminal branches of planter arteries supplying their collateral nerves have been seen in many cases.  Less commonly truncular arteritis, i.e. tuberculoid occlusion of major arteries are found.  Reactional changes are manifested as allergic vasculitis. Endarteritis, proliferation of endothelial cells, hyperplasia of intima, thrombosis within lumen, fibrinoid necrosis and infiltration within tunica media are noticed. Functional changes are spasmodic state of the vessels due to irritation of sympathetic nerves and entrapment of blood vessels in true groove or tunnel inside neuro-vascular bundles due to oedematous nerves.  All these types of vascular pathological processes may lead to impairment of digital microcirculation. Still, as our study revealed diminished digital flow only in paucibacillary patients suffering for > 2 years and the type or site of the lesions was not related to the degree of impairment, functional vascular changes seemed to play negligible role as underlying mechanism. Reactional vascular changes are also not much important contributory factors in the aetiopathogenesis of vascular impairment because the present study showed that the phase (reactional) of the disease had no bearing upon the degree of diminution in vascular flow. Hence, specific vascular changes contributed mostly to cause impairment in digital vascular flow as seen in this study.
In 2 patients, suffering for 1.5 years, increased digital blood flow was paradoxically seen which is probably due to reactive hyperaemia  or paralytic vasodilatation  due to auto-sympathectomy.
The present study suggests that the vasoactive drugs which can improve capillary flow may have definite role in the management of long-standing paucibacillary leprosy along with specific antileprosy medicines.
| References|| |
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|2.||Carayon A. Vascular changes in leprosy. In Leprosy, Volume 2, (Dharmendra, ed) 1st edn. Bombay : Samant and Company, 1985; 854-71. |
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[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5], [Figure - 6]