Background: Neuropathy is a common complication of diabetes mellitus (DM) with a wide clinical spectrum that encompasses generalized to focal and multifocal forms not only leads to an impaired quality of life, but also to an increased morbidity and mortality .  Till now there is no available effective therapy for the treatment of diabetic peripheral neuropathy (DPN). Autologous platelet-rich plasma is easy and cost-effective method as it provides necessary growth factors  that promote wound healing/growth, angiogenesis, and axon regeneration .
Objective: To evaluate the clinical efficacy and safety of peri-neural  injection of  platelet rich plasma (PRP)  in the treatment of diabetic peripheral neuropathy  compared to traditional medical treatment.
Method : Prospective double blinded randomized controlled trial was conducted (ClinicalTrials.gov Identifier: NCT03250403) . All included patients had type 2 DM selected from Endocrinology unit Department of Internal medicine, Assuit university Hospital, Egypt  .  DPN of at least 5 years duration of symptoms . Patients with other causes of neuropathy like hereditary neuropathies , entrapment neuropathies , overt neuropathy with foot ulcers and /or amputation , peripheral arterial diseases ,connective tissue diseases , vertebral diseases ,thyroid disorders and end organ failure were excluded . Neuropathy was assessed  by the modified Toronto Clinical Neuropathy Score  (mTCNS) 2009 (3) 
Symptom scores	Sensory test scores
Foot pain	Pinprick
Numbness	Temperature
Tingling	Light touch
Weakness	Vibration
Ataxia	Position Sense
Upper limb symptoms
Symptom scores graded as	Sensory test scores graded as
0 = absent	0 = normal
1 = present but no interference with sense of well-being or activities of daily living	1 = reduced at the toes only
2 = present, interferes with sense of well-being but not with activities of daily living	2 = reduced to a level above the toes, but only up to the ankles
3 = present and interferes with both sense of well-being and activities of daily living (both)	3 = reduced to a level above the ankles and/or absent at the toes
 Baseline pain and nerve conduction studies were done. Regardless of age and gender participants were double blindly divided into two groups, both the control and experimental groups received primary treatment (vitamin B complex, α lipoic acid, SSRI) and strictly control blood glucose. Group I underwent PRP peri-neural injection under ultrasound guidance    .  Group   װreceived  medical treatment  only( control group) . Blood glucose was strictly controlled in both  groups . Patients were followed every month for 3 months by  mTCNS  and by nerve conduction studies.  Results were expressed as means ± standard deviation or frequencies. Independent Student’s t test   and mann-whitney test were used for comparison between  groups
Results: the study included 60 type 2 diabetic patients with peripheral neuropathy , 33(55%)were female with a mean age (± SD) of 35.27 ± 12.86 years with duration of DPN 7.42 ± 1.51 years . Of these, there was 34/60 (56%) cases with lower limb neuropathy only.  while the rest (26/60) (44%) had both lower and upper limb nerves neuropathy, Nerve conduction study showed axonal affection in only 16/60 cases (26%) and 100% had delayed distal  latency and prolonged motor conduction velocities.40 patients underwent PRP peri-neural injection. Significant symptomatic  improvement in group I versus  group װ (P value ≤0.001). both  mean motor nerve conduction velocity of lower limb and Sural conduction velocity were accelerated  in group I after 6 months of application of PRP (P value ≤0.05, ≤0.001 respectivly), also mTCNS had improved in group I post PRP injection 10.6± 3.2 versus 21.3± 5.4 at baseline (P value ≤0.001).

Efficacy of platelet rich plasma injection in diabetic neuropathy: double blinded randomized controlled trial