A student who died after a night out may have died because of a combination of drugs, booze and concussion, an inquest heard.
Plymouth University student Hamish Howitt, 20, was found dead the morning after having been allegedly involved in a street fight where he was ‘rugby tackled’ to the ground.
After the fight, his pals helped him into bed at his digs in Frome, Somerset, but found him dead in the early hours of July 1, 2016, an inquest heard.
Avon and Somerset Constabulary previously said men identified as being involved in the fight through CCTV assisted them with their enquiries.
One man was arrested on suspicion of public disorder but was released with a police caution.
Three men were also arrested on suspicion of being concerned in drug supply, but were released without charge.
Toxicology reports found Hamish had an alcohol blood level one-and-a-half times over the drink-drive limit, and traces of ketamine in his system.
All of the experts now agree Hamish, from Chichester, West Sussex, did have a mild brain injury, but it is unclear whether it could have directly caused his death.
An inquest at Crawley Coroner’s Court is hearing from experts before they will be called to determine a cause of death together in a process called ‘hot tubbing’.
Assistant coroner Fiona King said: “We have struggled to identify a medical cause of death. It is for that reason we have called all the medical professionals today.
“There are areas of disagreement about what happened prior to that night.”
A forensic pathologist and neuropathologist initially said they could find no evidence Hamish had suffered a traumatic brain injury at a post-mortem.
But at the request of Hamish’s family, an expert in Glasgow carried out further microscopic tests and concluded he had a concussion akin to a “mild but complicated” brain injury.
The inquest first heard from forensic pathologist Dr Russell Delaney, who undertook a post-mortem the day after Hamish’s death, and found a number of recent grazes and bruises on his face.
Giving evidence, he said there was no evidence of bruising under the skin or skull except a “thin film” of blood on the brain called a subdural haemorrhage, which he could not find a reason for.
The pathologist also explained a fracture on Hamish’s skull was caused during the autopsy after death, which was “uncommon” but not unheard of.
He said Hamish would not have been able to walk home if the fracture had been caused while he was alive.
Dr Delaney said: “This is a high energy injury and something we would more commonly see in a road traffic collision, a fall from a height or an explosion.”
Toxicologist Peter Beresford told the inquest Hamish had a blood-alcohol level of 132 micrograms per 100ml in blood, and 0.44mg of ketamine in 100ml of blood.
He said ketamine caused an “anaesthetic effect” but studies found just over 2mg was needed to render you unconscious.
The inquest also heard a blood alcohol level of over 130mg is considered to “impair motor function” and over 150mg could cause “respiratory depression”.
Neuropathologist Dr Kathryn Urankar studied Hamish’s brain after the post-mortem and said she did not see any injuries to the brain or find any “underlying abnormalities”.
She said the film of blood on the brain was not significant enough to cause Hamish’s death and agreed the skull fracture was caused at the post-mortem.
Asked about the combined effect of alcohol and ketamine on the body, Dr Urankar said: “Ketamine is an anesthetic and is supposed to suppress your consciousness. You are going to get a combined effect of the two.”
Professor William Stewart, a neuropathologist at the University of Glasgow, was approached by Hamish’s family through a charity and asked to look at the medical reports.
He requested brain samples and found evidence of concussion, also known as a mild brain injury, in the fibres passing through the middle of the brain.
Professor Stewart said: “It’s highly significant because this is evidence of trauma. It’s at the far end, mild. It’s still enough to lead to symptoms such as irritability, altered behaviour, drowsiness, feeling in a fog and loss of consciousness.
“These injuries can be asymptomatic in the beginning but in a matter of hours can be very serious.
“In this case what we are looking at is a ‘complicated mild’, it’s what appears to be mild on the surface but we have a subdural haemorrhage there. That excludes it from a simple mild brain injury to one where a hospital would want to keep you in and look after you.”
He added: “The reason people with a head injury on a Friday night while having been drinking are generally kept on observation wards is we can’t separate the symptoms of being drunk with symptoms of a head injury.
“The drugs and alcohol can mask the significant symptoms of a brain injury.”
Dr Urankar compiled a second report after seeing Professor Stewart’s analysis and “conceded” there was evidence Hamish had a mild brain injury.
She said: “We have all been arguing over significance, whether it’s mild and causes death or contributes to death. My point of view is it didn’t cause death, it’s not of a severe enough nature to cause death.
“It is possible there may have been some contribution of the injury to Hamish’s death, I can’t exclude it in its entirety.”
A third neuropathologist Dr Safa Al-Sarraj from King’s College London, also agreed with the conclusion that Hamish had a “mild” brain injury – but could not agree it led to his death.
He said: “My only concern is that the patient had survived and was well for some time.
“In my opinion the contribution to death is minimum. If he had died immediately after the trauma I would have agreed that it is right it had a major contribution.”
The inquest continues tomorrow.